From a1580d7b59b65b17f2ce7fdb95f46379e7df4089 Mon Sep 17 00:00:00 2001
From: Kazu Hirata <kazu@google.com>
Date: Sat, 14 Jan 2023 11:07:21 -0800
Subject: [PATCH] [clang] Add #include <optional> (NFC)

This patch adds #include <optional> to those files containing
llvm::Optional<...> or Optional<...>.

I'll post a separate patch to actually replace llvm::Optional with
std::optional.

This is part of an effort to migrate from llvm::Optional to
std::optional:

https://discourse.llvm.org/t/deprecating-llvm-optional-x-hasvalue-getvalue-getvalueor/63716
---
 clang/include/clang/AST/ASTContext.h                                     | 1 +
 clang/include/clang/AST/ASTImporter.h                                    | 1 +
 clang/include/clang/AST/ASTImporterSharedState.h                         | 1 +
 clang/include/clang/AST/ASTStructuralEquivalence.h                       | 1 +
 clang/include/clang/AST/AbstractBasicReader.h                            | 1 +
 clang/include/clang/AST/AbstractBasicWriter.h                            | 1 +
 clang/include/clang/AST/ComparisonCategories.h                           | 1 +
 clang/include/clang/AST/Decl.h                                           | 1 +
 clang/include/clang/AST/DeclTemplate.h                                   | 1 +
 clang/include/clang/AST/Expr.h                                           | 1 +
 clang/include/clang/AST/ExprCXX.h                                        | 1 +
 clang/include/clang/AST/ExprObjC.h                                       | 1 +
 clang/include/clang/AST/ExternalASTSource.h                              | 1 +
 clang/include/clang/AST/FormatString.h                                   | 1 +
 clang/include/clang/AST/Mangle.h                                         | 1 +
 clang/include/clang/AST/NSAPI.h                                          | 1 +
 clang/include/clang/AST/Stmt.h                                           | 1 +
 clang/include/clang/AST/TemplateBase.h                                   | 1 +
 clang/include/clang/AST/TemplateName.h                                   | 1 +
 clang/include/clang/AST/Type.h                                           | 1 +
 clang/include/clang/ASTMatchers/ASTMatchFinder.h                         | 1 +
 clang/include/clang/ASTMatchers/ASTMatchers.h                            | 1 +
 clang/include/clang/ASTMatchers/ASTMatchersInternal.h                    | 1 +
 clang/include/clang/ASTMatchers/Dynamic/Parser.h                         | 1 +
 clang/include/clang/ASTMatchers/Dynamic/Registry.h                       | 1 +
 clang/include/clang/ASTMatchers/Dynamic/VariantValue.h                   | 1 +
 clang/include/clang/Analysis/Analyses/ThreadSafetyTIL.h                  | 1 +
 clang/include/clang/Analysis/AnyCall.h                                   | 1 +
 clang/include/clang/Analysis/BodyFarm.h                                  | 1 +
 clang/include/clang/Analysis/CFG.h                                       | 1 +
 clang/include/clang/Analysis/FlowSensitive/DataflowAnalysis.h            | 1 +
 clang/include/clang/Analysis/FlowSensitive/DataflowAnalysisContext.h     | 1 +
 clang/include/clang/Analysis/FlowSensitive/Solver.h                      | 1 +
 clang/include/clang/Analysis/FlowSensitive/TypeErasedDataflowAnalysis.h  | 1 +
 clang/include/clang/Analysis/MacroExpansionContext.h                     | 1 +
 clang/include/clang/Analysis/PathDiagnostic.h                            | 1 +
 clang/include/clang/Analysis/ProgramPoint.h                              | 1 +
 clang/include/clang/Analysis/RetainSummaryManager.h                      | 1 +
 clang/include/clang/Basic/DarwinSDKInfo.h                                | 1 +
 clang/include/clang/Basic/Diagnostic.h                                   | 1 +
 clang/include/clang/Basic/DiagnosticError.h                              | 1 +
 clang/include/clang/Basic/DiagnosticIDs.h                                | 1 +
 clang/include/clang/Basic/DirectoryEntry.h                               | 1 +
 clang/include/clang/Basic/FileEntry.h                                    | 1 +
 clang/include/clang/Basic/FileSystemStatCache.h                          | 1 +
 clang/include/clang/Basic/LangOptions.h                                  | 1 +
 clang/include/clang/Basic/Module.h                                       | 1 +
 clang/include/clang/Basic/ProfileList.h                                  | 1 +
 clang/include/clang/Basic/Sarif.h                                        | 1 +
 clang/include/clang/Basic/SourceManager.h                                | 1 +
 clang/include/clang/CrossTU/CrossTranslationUnit.h                       | 1 +
 clang/include/clang/ExtractAPI/Serialization/SymbolGraphSerializer.h     | 1 +
 clang/include/clang/Format/Format.h                                      | 1 +
 clang/include/clang/Frontend/ASTUnit.h                                   | 1 +
 clang/include/clang/Frontend/CommandLineSourceLoc.h                      | 1 +
 clang/include/clang/Frontend/CompilerInstance.h                          | 1 +
 clang/include/clang/Frontend/FrontendOptions.h                           | 1 +
 clang/include/clang/Lex/HeaderMap.h                                      | 1 +
 clang/include/clang/Lex/Lexer.h                                          | 1 +
 clang/include/clang/Lex/ModuleMap.h                                      | 1 +
 clang/include/clang/Lex/PreprocessingRecord.h                            | 1 +
 clang/include/clang/Lex/Preprocessor.h                                   | 1 +
 clang/include/clang/Lex/PreprocessorOptions.h                            | 1 +
 clang/include/clang/Parse/Parser.h                                       | 1 +
 clang/include/clang/Sema/CodeCompleteConsumer.h                          | 1 +
 clang/include/clang/Sema/Lookup.h                                        | 1 +
 clang/include/clang/Sema/Scope.h                                         | 1 +
 clang/include/clang/Sema/Sema.h                                          | 1 +
 clang/include/clang/Sema/SemaConcept.h                                   | 1 +
 clang/include/clang/Sema/SemaLambda.h                                    | 1 +
 clang/include/clang/Sema/Template.h                                      | 1 +
 clang/include/clang/Sema/TemplateDeduction.h                             | 1 +
 clang/include/clang/Serialization/ASTReader.h                            | 1 +
 clang/include/clang/StaticAnalyzer/Core/BugReporter/BugReporter.h        | 1 +
 .../include/clang/StaticAnalyzer/Core/BugReporter/BugReporterVisitors.h  | 1 +
 clang/include/clang/StaticAnalyzer/Core/PathSensitive/CallDescription.h  | 1 +
 clang/include/clang/StaticAnalyzer/Core/PathSensitive/CallEvent.h        | 1 +
 clang/include/clang/StaticAnalyzer/Core/PathSensitive/CheckerContext.h   | 1 +
 clang/include/clang/StaticAnalyzer/Core/PathSensitive/CheckerHelpers.h   | 1 +
 .../include/clang/StaticAnalyzer/Core/PathSensitive/ConstraintManager.h  | 1 +
 clang/include/clang/StaticAnalyzer/Core/PathSensitive/ExplodedGraph.h    | 1 +
 clang/include/clang/StaticAnalyzer/Core/PathSensitive/ExprEngine.h       | 1 +
 clang/include/clang/StaticAnalyzer/Core/PathSensitive/FunctionSummary.h  | 1 +
 clang/include/clang/StaticAnalyzer/Core/PathSensitive/MemRegion.h        | 1 +
 clang/include/clang/StaticAnalyzer/Core/PathSensitive/ProgramState.h     | 1 +
 .../clang/StaticAnalyzer/Core/PathSensitive/SMTConstraintManager.h       | 1 +
 clang/include/clang/StaticAnalyzer/Core/PathSensitive/SValBuilder.h      | 1 +
 clang/include/clang/StaticAnalyzer/Core/PathSensitive/SVals.h            | 1 +
 clang/include/clang/StaticAnalyzer/Core/PathSensitive/Store.h            | 1 +
 clang/include/clang/Tooling/ASTDiff/ASTDiff.h                            | 1 +
 clang/include/clang/Tooling/AllTUsExecution.h                            | 1 +
 clang/include/clang/Tooling/Core/Replacement.h                           | 1 +
 .../clang/Tooling/DependencyScanning/DependencyScanningFilesystem.h      | 1 +
 clang/include/clang/Tooling/DependencyScanning/DependencyScanningTool.h  | 1 +
 .../include/clang/Tooling/DependencyScanning/DependencyScanningWorker.h  | 1 +
 clang/include/clang/Tooling/Inclusions/HeaderIncludes.h                  | 1 +
 clang/include/clang/Tooling/Refactoring/ASTSelection.h                   | 1 +
 clang/include/clang/Tooling/Refactoring/Extract/Extract.h                | 1 +
 clang/include/clang/Tooling/Refactoring/RefactoringOptionVisitor.h       | 1 +
 clang/include/clang/Tooling/Refactoring/RefactoringOptions.h             | 1 +
 clang/include/clang/Tooling/StandaloneExecution.h                        | 1 +
 clang/lib/ARCMigrate/Internals.h                                         | 1 +
 clang/lib/AST/AttrImpl.cpp                                               | 1 +
 clang/lib/AST/ComparisonCategories.cpp                                   | 1 +
 clang/lib/AST/Decl.cpp                                                   | 1 +
 clang/lib/AST/DeclTemplate.cpp                                           | 1 +
 clang/lib/AST/Expr.cpp                                                   | 1 +
 clang/lib/AST/ExprCXX.cpp                                                | 1 +
 clang/lib/AST/ExternalASTSource.cpp                                      | 1 +
 clang/lib/AST/FormatString.cpp                                           | 1 +
 clang/lib/AST/ItaniumCXXABI.cpp                                          | 1 +
 clang/lib/AST/ItaniumMangle.cpp                                          | 1 +
 clang/lib/AST/JSONNodeDumper.cpp                                         | 1 +
 clang/lib/AST/Linkage.h                                                  | 1 +
 clang/lib/AST/MicrosoftMangle.cpp                                        | 1 +
 clang/lib/AST/NSAPI.cpp                                                  | 1 +
 clang/lib/AST/OpenMPClause.cpp                                           | 1 +
 clang/lib/AST/Stmt.cpp                                                   | 1 +
 clang/lib/AST/StmtPrinter.cpp                                            | 1 +
 clang/lib/AST/TemplateBase.cpp                                           | 1 +
 clang/lib/AST/TemplateName.cpp                                           | 1 +
 clang/lib/AST/Type.cpp                                                   | 1 +
 clang/lib/ASTMatchers/ASTMatchersInternal.cpp                            | 1 +
 clang/lib/ASTMatchers/Dynamic/Marshallers.cpp                            | 1 +
 clang/lib/ASTMatchers/Dynamic/Marshallers.h                              | 1 +
 clang/lib/ASTMatchers/Dynamic/Parser.cpp                                 | 1 +
 clang/lib/ASTMatchers/Dynamic/Registry.cpp                               | 1 +
 clang/lib/ASTMatchers/Dynamic/VariantValue.cpp                           | 1 +
 clang/lib/Analysis/BodyFarm.cpp                                          | 1 +
 clang/lib/Analysis/CFG.cpp                                               | 1 +
 clang/lib/Analysis/CFGStmtMap.cpp                                        | 1 +
 clang/lib/Analysis/CalledOnceCheck.cpp                                   | 1 +
 clang/lib/Analysis/Consumed.cpp                                          | 1 +
 clang/lib/Analysis/FlowSensitive/Models/UncheckedOptionalAccessModel.cpp | 1 +
 clang/lib/Analysis/FlowSensitive/TypeErasedDataflowAnalysis.cpp          | 1 +
 clang/lib/Analysis/IssueHash.cpp                                         | 1 +
 clang/lib/Analysis/LiveVariables.cpp                                     | 1 +
 clang/lib/Analysis/MacroExpansionContext.cpp                             | 1 +
 clang/lib/Analysis/PathDiagnostic.cpp                                    | 1 +
 clang/lib/Analysis/ReachableCode.cpp                                     | 1 +
 clang/lib/Analysis/RetainSummaryManager.cpp                              | 1 +
 clang/lib/Analysis/ThreadSafety.cpp                                      | 1 +
 clang/lib/Analysis/UninitializedValues.cpp                               | 1 +
 clang/lib/Analysis/UnsafeBufferUsage.cpp                                 | 1 +
 clang/lib/Basic/DiagnosticIDs.cpp                                        | 1 +
 clang/lib/Basic/ProfileList.cpp                                          | 1 +
 clang/lib/Basic/Sarif.cpp                                                | 1 +
 clang/lib/Basic/SourceManager.cpp                                        | 1 +
 clang/lib/Basic/Targets/AArch64.cpp                                      | 1 +
 clang/lib/Basic/Targets/AArch64.h                                        | 1 +
 clang/lib/Basic/Targets/M68k.cpp                                         | 1 +
 clang/lib/Basic/Targets/M68k.h                                           | 1 +
 clang/lib/Basic/Targets/RISCV.h                                          | 1 +
 clang/lib/Basic/Targets/X86.cpp                                          | 1 +
 clang/lib/Basic/Targets/X86.h                                            | 1 +
 clang/lib/CodeGen/CGBuiltin.cpp                                          | 1 +
 clang/lib/CodeGen/CGClass.cpp                                            | 1 +
 clang/lib/CodeGen/CGDecl.cpp                                             | 1 +
 clang/lib/CodeGen/CGExpr.cpp                                             | 1 +
 clang/lib/CodeGen/CGExprConstant.cpp                                     | 1 +
 clang/lib/CodeGen/CGExprScalar.cpp                                       | 1 +
 clang/lib/CodeGen/CGHLSLRuntime.h                                        | 1 +
 clang/lib/CodeGen/CGLoopInfo.cpp                                         | 1 +
 clang/lib/CodeGen/CGObjC.cpp                                             | 1 +
 clang/lib/CodeGen/CGOpenMPRuntime.cpp                                    | 1 +
 clang/lib/CodeGen/CGStmt.cpp                                             | 1 +
 clang/lib/CodeGen/CGStmtOpenMP.cpp                                       | 1 +
 clang/lib/CodeGen/CodeGenAction.cpp                                      | 1 +
 clang/lib/CodeGen/CodeGenFunction.cpp                                    | 1 +
 clang/lib/CodeGen/CodeGenFunction.h                                      | 1 +
 clang/lib/CodeGen/CodeGenModule.cpp                                      | 1 +
 clang/lib/CodeGen/CodeGenModule.h                                        | 1 +
 clang/lib/CodeGen/CodeGenPGO.cpp                                         | 1 +
 clang/lib/CodeGen/CodeGenPGO.h                                           | 1 +
 clang/lib/CodeGen/CoverageMappingGen.cpp                                 | 1 +
 clang/lib/CodeGen/SwiftCallingConv.cpp                                   | 1 +
 clang/lib/CrossTU/CrossTranslationUnit.cpp                               | 1 +
 clang/lib/Edit/RewriteObjCFoundationAPI.cpp                              | 1 +
 clang/lib/ExtractAPI/Serialization/SymbolGraphSerializer.cpp             | 1 +
 clang/lib/Format/ContinuationIndenter.h                                  | 1 +
 clang/lib/Format/FormatToken.h                                           | 1 +
 clang/lib/Frontend/DependencyFile.cpp                                    | 1 +
 clang/lib/Frontend/FrontendActions.cpp                                   | 1 +
 clang/lib/Lex/DependencyDirectivesScanner.cpp                            | 1 +
 clang/lib/Lex/HeaderMap.cpp                                              | 1 +
 clang/lib/Lex/InitHeaderSearch.cpp                                       | 1 +
 clang/lib/Lex/Lexer.cpp                                                  | 1 +
 clang/lib/Lex/MacroInfo.cpp                                              | 1 +
 clang/lib/Lex/ModuleMap.cpp                                              | 1 +
 clang/lib/Lex/PPDirectives.cpp                                           | 1 +
 clang/lib/Lex/PPLexerChange.cpp                                          | 1 +
 clang/lib/Lex/PPMacroExpansion.cpp                                       | 1 +
 clang/lib/Lex/Pragma.cpp                                                 | 1 +
 clang/lib/Lex/PreprocessingRecord.cpp                                    | 1 +
 clang/lib/Lex/Preprocessor.cpp                                           | 1 +
 clang/lib/Lex/TokenLexer.cpp                                             | 1 +
 clang/lib/Parse/ParseDecl.cpp                                            | 1 +
 clang/lib/Parse/ParseDeclCXX.cpp                                         | 1 +
 clang/lib/Parse/ParseExpr.cpp                                            | 1 +
 clang/lib/Parse/ParseOpenMP.cpp                                          | 1 +
 clang/lib/Parse/ParsePragma.cpp                                          | 1 +
 clang/lib/Parse/ParseStmt.cpp                                            | 1 +
 clang/lib/Sema/AnalysisBasedWarnings.cpp                                 | 1 +
 clang/lib/Sema/Sema.cpp                                                  | 1 +
 clang/lib/Sema/SemaAttr.cpp                                              | 1 +
 clang/lib/Sema/SemaAvailability.cpp                                      | 1 +
 clang/lib/Sema/SemaCUDA.cpp                                              | 1 +
 clang/lib/Sema/SemaChecking.cpp                                          | 1 +
 clang/lib/Sema/SemaCodeComplete.cpp                                      | 1 +
 clang/lib/Sema/SemaConcept.cpp                                           | 1 +
 clang/lib/Sema/SemaDecl.cpp                                              | 1 +
 clang/lib/Sema/SemaDeclAttr.cpp                                          | 1 +
 clang/lib/Sema/SemaDeclCXX.cpp                                           | 1 +
 clang/lib/Sema/SemaExceptionSpec.cpp                                     | 1 +
 clang/lib/Sema/SemaExpr.cpp                                              | 1 +
 clang/lib/Sema/SemaExprCXX.cpp                                           | 1 +
 clang/lib/Sema/SemaExprObjC.cpp                                          | 1 +
 clang/lib/Sema/SemaLambda.cpp                                            | 1 +
 clang/lib/Sema/SemaLookup.cpp                                            | 1 +
 clang/lib/Sema/SemaModule.cpp                                            | 1 +
 clang/lib/Sema/SemaOpenMP.cpp                                            | 1 +
 clang/lib/Sema/SemaRISCVVectorLookup.cpp                                 | 1 +
 clang/lib/Sema/SemaStmtAsm.cpp                                           | 1 +
 clang/lib/Sema/SemaStmtAttr.cpp                                          | 1 +
 clang/lib/Sema/SemaTemplate.cpp                                          | 1 +
 clang/lib/Sema/SemaTemplateDeduction.cpp                                 | 1 +
 clang/lib/Sema/SemaTemplateInstantiate.cpp                               | 1 +
 clang/lib/Sema/SemaTemplateInstantiateDecl.cpp                           | 1 +
 clang/lib/Sema/SemaTemplateVariadic.cpp                                  | 1 +
 clang/lib/Sema/SemaType.cpp                                              | 1 +
 clang/lib/Sema/TreeTransform.h                                           | 1 +
 clang/lib/Serialization/ASTReader.cpp                                    | 1 +
 clang/lib/Serialization/ASTReaderStmt.cpp                                | 1 +
 clang/lib/Serialization/ASTWriter.cpp                                    | 1 +
 clang/lib/Serialization/ASTWriterDecl.cpp                                | 1 +
 clang/lib/StaticAnalyzer/Checkers/AnalyzerStatsChecker.cpp               | 1 +
 clang/lib/StaticAnalyzer/Checkers/ArrayBoundCheckerV2.cpp                | 1 +
 clang/lib/StaticAnalyzer/Checkers/BoolAssignmentChecker.cpp              | 1 +
 clang/lib/StaticAnalyzer/Checkers/CStringChecker.cpp                     | 1 +
 clang/lib/StaticAnalyzer/Checkers/CastValueChecker.cpp                   | 1 +
 clang/lib/StaticAnalyzer/Checkers/CheckObjCDealloc.cpp                   | 1 +
 clang/lib/StaticAnalyzer/Checkers/DivZeroChecker.cpp                     | 1 +
 clang/lib/StaticAnalyzer/Checkers/DynamicTypePropagation.cpp             | 1 +
 clang/lib/StaticAnalyzer/Checkers/EnumCastOutOfRangeChecker.cpp          | 1 +
 clang/lib/StaticAnalyzer/Checkers/ErrnoChecker.cpp                       | 1 +
 clang/lib/StaticAnalyzer/Checkers/ErrnoModeling.cpp                      | 1 +
 clang/lib/StaticAnalyzer/Checkers/ErrnoModeling.h                        | 1 +
 clang/lib/StaticAnalyzer/Checkers/ErrnoTesterChecker.cpp                 | 1 +
 clang/lib/StaticAnalyzer/Checkers/ExprInspectionChecker.cpp              | 1 +
 clang/lib/StaticAnalyzer/Checkers/FuchsiaHandleChecker.cpp               | 1 +
 clang/lib/StaticAnalyzer/Checkers/GTestChecker.cpp                       | 1 +
 clang/lib/StaticAnalyzer/Checkers/LocalizationChecker.cpp                | 1 +
 clang/lib/StaticAnalyzer/Checkers/MIGChecker.cpp                         | 1 +
 clang/lib/StaticAnalyzer/Checkers/MacOSKeychainAPIChecker.cpp            | 1 +
 clang/lib/StaticAnalyzer/Checkers/MallocOverflowSecurityChecker.cpp      | 1 +
 clang/lib/StaticAnalyzer/Checkers/NSErrorChecker.cpp                     | 1 +
 clang/lib/StaticAnalyzer/Checkers/NonnullGlobalConstantsChecker.cpp      | 1 +
 .../StaticAnalyzer/Checkers/RetainCountChecker/RetainCountChecker.cpp    | 1 +
 clang/lib/StaticAnalyzer/Checkers/ReturnValueChecker.cpp                 | 1 +
 clang/lib/StaticAnalyzer/Checkers/SmartPtrModeling.cpp                   | 1 +
 clang/lib/StaticAnalyzer/Checkers/StreamChecker.cpp                      | 1 +
 clang/lib/StaticAnalyzer/Checkers/Taint.cpp                              | 1 +
 clang/lib/StaticAnalyzer/Checkers/TestAfterDivZeroChecker.cpp            | 1 +
 clang/lib/StaticAnalyzer/Checkers/UndefBranchChecker.cpp                 | 1 +
 clang/lib/StaticAnalyzer/Checkers/UndefCapturedBlockVarChecker.cpp       | 1 +
 .../StaticAnalyzer/Checkers/UninitializedObject/UninitializedPointee.cpp | 1 +
 clang/lib/StaticAnalyzer/Checkers/UnreachableCodeChecker.cpp             | 1 +
 clang/lib/StaticAnalyzer/Checkers/VLASizeChecker.cpp                     | 1 +
 clang/lib/StaticAnalyzer/Checkers/VforkChecker.cpp                       | 1 +
 clang/lib/StaticAnalyzer/Checkers/WebKit/ASTUtils.cpp                    | 1 +
 clang/lib/StaticAnalyzer/Checkers/WebKit/NoUncountedMembersChecker.cpp   | 1 +
 clang/lib/StaticAnalyzer/Checkers/WebKit/PtrTypesSemantics.cpp           | 1 +
 .../StaticAnalyzer/Checkers/WebKit/RefCntblBaseVirtualDtorChecker.cpp    | 1 +
 clang/lib/StaticAnalyzer/Checkers/WebKit/UncountedCallArgsChecker.cpp    | 1 +
 .../StaticAnalyzer/Checkers/WebKit/UncountedLambdaCapturesChecker.cpp    | 1 +
 clang/lib/StaticAnalyzer/Checkers/WebKit/UncountedLocalVarsChecker.cpp   | 1 +
 clang/lib/StaticAnalyzer/Checkers/Yaml.h                                 | 1 +
 clang/lib/StaticAnalyzer/Core/AnalyzerOptions.cpp                        | 1 +
 clang/lib/StaticAnalyzer/Core/BugReporter.cpp                            | 1 +
 clang/lib/StaticAnalyzer/Core/BugReporterVisitors.cpp                    | 1 +
 clang/lib/StaticAnalyzer/Core/CallDescription.cpp                        | 1 +
 clang/lib/StaticAnalyzer/Core/CallEvent.cpp                              | 1 +
 clang/lib/StaticAnalyzer/Core/CheckerHelpers.cpp                         | 1 +
 clang/lib/StaticAnalyzer/Core/CheckerManager.cpp                         | 1 +
 clang/lib/StaticAnalyzer/Core/CoreEngine.cpp                             | 1 +
 clang/lib/StaticAnalyzer/Core/ExplodedGraph.cpp                          | 1 +
 clang/lib/StaticAnalyzer/Core/ExprEngine.cpp                             | 1 +
 clang/lib/StaticAnalyzer/Core/ExprEngineC.cpp                            | 1 +
 clang/lib/StaticAnalyzer/Core/ExprEngineCXX.cpp                          | 1 +
 clang/lib/StaticAnalyzer/Core/ExprEngineCallAndReturn.cpp                | 1 +
 clang/lib/StaticAnalyzer/Core/LoopUnrolling.cpp                          | 1 +
 clang/lib/StaticAnalyzer/Core/MemRegion.cpp                              | 1 +
 clang/lib/StaticAnalyzer/Core/PlistDiagnostics.cpp                       | 1 +
 clang/lib/StaticAnalyzer/Core/ProgramState.cpp                           | 1 +
 clang/lib/StaticAnalyzer/Core/RangeConstraintManager.cpp                 | 1 +
 clang/lib/StaticAnalyzer/Core/RegionStore.cpp                            | 1 +
 clang/lib/StaticAnalyzer/Core/SValBuilder.cpp                            | 1 +
 clang/lib/StaticAnalyzer/Core/SVals.cpp                                  | 1 +
 clang/lib/StaticAnalyzer/Core/SimpleConstraintManager.cpp                | 1 +
 clang/lib/StaticAnalyzer/Core/SimpleSValBuilder.cpp                      | 1 +
 clang/lib/StaticAnalyzer/Core/Store.cpp                                  | 1 +
 clang/lib/Tooling/ASTDiff/ASTDiff.cpp                                    | 1 +
 clang/lib/Tooling/DependencyScanning/DependencyScanningFilesystem.cpp    | 1 +
 clang/lib/Tooling/DependencyScanning/DependencyScanningTool.cpp          | 1 +
 clang/lib/Tooling/DependencyScanning/DependencyScanningWorker.cpp        | 1 +
 clang/lib/Tooling/DependencyScanning/ModuleDepCollector.cpp              | 1 +
 clang/lib/Tooling/Inclusions/HeaderIncludes.cpp                          | 1 +
 clang/lib/Tooling/InterpolatingCompilationDatabase.cpp                   | 1 +
 clang/lib/Tooling/JSONCompilationDatabase.cpp                            | 1 +
 clang/lib/Tooling/Refactoring/ASTSelection.cpp                           | 1 +
 clang/lib/Tooling/Refactoring/ASTSelectionRequirements.cpp               | 1 +
 clang/lib/Tooling/Refactoring/Extract/Extract.cpp                        | 1 +
 clang/lib/Tooling/Refactoring/Extract/SourceExtraction.cpp               | 1 +
 clang/lib/Tooling/Syntax/Tokens.cpp                                      | 1 +
 clang/lib/Tooling/Transformer/Parsing.cpp                                | 1 +
 clang/tools/clang-extdef-mapping/ClangExtDefMapGen.cpp                   | 1 +
 clang/tools/clang-refactor/ClangRefactor.cpp                             | 1 +
 clang/tools/clang-refactor/TestSupport.cpp                               | 1 +
 clang/tools/clang-refactor/TestSupport.h                                 | 1 +
 clang/tools/clang-repl/ClangRepl.cpp                                     | 1 +
 clang/tools/clang-scan-deps/ClangScanDeps.cpp                            | 1 +
 clang/tools/diagtool/FindDiagnosticID.cpp                                | 1 +
 clang/tools/driver/cc1as_main.cpp                                        | 1 +
 clang/tools/driver/cc1gen_reproducer_main.cpp                            | 1 +
 clang/tools/libclang/CIndex.cpp                                          | 1 +
 clang/tools/libclang/CXType.cpp                                          | 1 +
 clang/tools/libclang/CursorVisitor.h                                     | 1 +
 clang/unittests/AST/ASTImporterTest.cpp                                  | 1 +
 clang/unittests/ASTMatchers/Dynamic/ParserTest.cpp                       | 1 +
 clang/unittests/ASTMatchers/Dynamic/RegistryTest.cpp                     | 1 +
 .../unittests/Analysis/FlowSensitive/MultiVarConstantPropagationTest.cpp | 1 +
 .../Analysis/FlowSensitive/SingleVarConstantPropagationTest.cpp          | 1 +
 clang/unittests/Analysis/FlowSensitive/TestingSupport.h                  | 1 +
 clang/unittests/Analysis/FlowSensitive/TransferBranchTest.cpp            | 1 +
 clang/unittests/Analysis/FlowSensitive/TransferTest.cpp                  | 1 +
 .../unittests/Analysis/FlowSensitive/TypeErasedDataflowAnalysisTest.cpp  | 1 +
 .../Analysis/FlowSensitive/UncheckedOptionalAccessModelTest.cpp          | 1 +
 clang/unittests/Basic/DarwinSDKInfoTest.cpp                              | 1 +
 clang/unittests/Basic/DiagnosticTest.cpp                                 | 1 +
 clang/unittests/Driver/SanitizerArgsTest.cpp                             | 1 +
 clang/unittests/Frontend/ParsedSourceLocationTest.cpp                    | 1 +
 clang/unittests/Lex/PPDependencyDirectivesTest.cpp                       | 1 +
 clang/unittests/Serialization/SourceLocationEncodingTest.cpp             | 1 +
 clang/unittests/StaticAnalyzer/TestReturnValueUnderConstruction.cpp      | 1 +
 clang/unittests/Tooling/ASTSelectionTest.cpp                             | 1 +
 clang/unittests/Tooling/RefactoringActionRulesTest.cpp                   | 1 +
 clang/unittests/Tooling/RefactoringTest.cpp                              | 1 +
 clang/unittests/Tooling/SourceCodeBuildersTest.cpp                       | 1 +
 clang/unittests/Tooling/StencilTest.cpp                                  | 1 +
 clang/unittests/Tooling/Syntax/TokensTest.cpp                            | 1 +
 clang/unittests/Tooling/TransformerTest.cpp                              | 1 +
 clang/utils/TableGen/ASTTableGen.cpp                                     | 1 +
 clang/utils/TableGen/ASTTableGen.h                                       | 1 +
 clang/utils/TableGen/ClangASTPropertiesEmitter.cpp                       | 1 +
 clang/utils/TableGen/ClangAttrEmitter.cpp                                | 1 +
 355 files changed, 355 insertions(+)

diff --git a/clang/include/clang/AST/ASTContext.h b/clang/include/clang/AST/ASTContext.h
index 4c0f507..ba255b7 100644
--- a/clang/include/clang/AST/ASTContext.h
+++ b/clang/include/clang/AST/ASTContext.h
@@ -46,6 +46,7 @@
 #include "llvm/ADT/StringRef.h"
 #include "llvm/ADT/TinyPtrVector.h"
 #include "llvm/Support/TypeSize.h"
+#include <optional>
 
 namespace llvm {
 
diff --git a/clang/include/clang/AST/ASTImporter.h b/clang/include/clang/AST/ASTImporter.h
index a6bb0e8..690ddce 100644
--- a/clang/include/clang/AST/ASTImporter.h
+++ b/clang/include/clang/AST/ASTImporter.h
@@ -29,6 +29,7 @@
 #include "llvm/ADT/DenseSet.h"
 #include "llvm/ADT/Optional.h"
 #include "llvm/ADT/SmallVector.h"
+#include <optional>
 #include <utility>
 
 namespace clang {
diff --git a/clang/include/clang/AST/ASTImporterSharedState.h b/clang/include/clang/AST/ASTImporterSharedState.h
index 27f27a5..519ed27 100644
--- a/clang/include/clang/AST/ASTImporterSharedState.h
+++ b/clang/include/clang/AST/ASTImporterSharedState.h
@@ -18,6 +18,7 @@
 #include "clang/AST/ASTImporterLookupTable.h"
 #include "clang/AST/Decl.h"
 #include "llvm/ADT/DenseMap.h"
+#include <optional>
 
 namespace clang {
 
diff --git a/clang/include/clang/AST/ASTStructuralEquivalence.h b/clang/include/clang/AST/ASTStructuralEquivalence.h
index 0b9e9e4..4550b50 100644
--- a/clang/include/clang/AST/ASTStructuralEquivalence.h
+++ b/clang/include/clang/AST/ASTStructuralEquivalence.h
@@ -18,6 +18,7 @@
 #include "llvm/ADT/DenseMap.h"
 #include "llvm/ADT/DenseSet.h"
 #include "llvm/ADT/Optional.h"
+#include <optional>
 #include <queue>
 #include <utility>
 
diff --git a/clang/include/clang/AST/AbstractBasicReader.h b/clang/include/clang/AST/AbstractBasicReader.h
index bb589fb..ea28b4e 100644
--- a/clang/include/clang/AST/AbstractBasicReader.h
+++ b/clang/include/clang/AST/AbstractBasicReader.h
@@ -10,6 +10,7 @@
 #define LLVM_CLANG_AST_ABSTRACTBASICREADER_H
 
 #include "clang/AST/DeclTemplate.h"
+#include <optional>
 
 namespace clang {
 namespace serialization {
diff --git a/clang/include/clang/AST/AbstractBasicWriter.h b/clang/include/clang/AST/AbstractBasicWriter.h
index 41772ba..6624a6e 100644
--- a/clang/include/clang/AST/AbstractBasicWriter.h
+++ b/clang/include/clang/AST/AbstractBasicWriter.h
@@ -11,6 +11,7 @@
 
 #include "clang/AST/ASTContext.h"
 #include "clang/AST/DeclTemplate.h"
+#include <optional>
 
 namespace clang {
 namespace serialization {
diff --git a/clang/include/clang/AST/ComparisonCategories.h b/clang/include/clang/AST/ComparisonCategories.h
index 7b73b58..aac8124 100644
--- a/clang/include/clang/AST/ComparisonCategories.h
+++ b/clang/include/clang/AST/ComparisonCategories.h
@@ -19,6 +19,7 @@
 #include "llvm/ADT/DenseMap.h"
 #include <array>
 #include <cassert>
+#include <optional>
 #include <vector>
 
 namespace llvm {
diff --git a/clang/include/clang/AST/Decl.h b/clang/include/clang/AST/Decl.h
index e9719fd..388cb51 100644
--- a/clang/include/clang/AST/Decl.h
+++ b/clang/include/clang/AST/Decl.h
@@ -46,6 +46,7 @@
 #include <cassert>
 #include <cstddef>
 #include <cstdint>
+#include <optional>
 #include <string>
 #include <utility>
 
diff --git a/clang/include/clang/AST/DeclTemplate.h b/clang/include/clang/AST/DeclTemplate.h
index b7032d00..085bd2e 100644
--- a/clang/include/clang/AST/DeclTemplate.h
+++ b/clang/include/clang/AST/DeclTemplate.h
@@ -39,6 +39,7 @@
 #include <cstddef>
 #include <cstdint>
 #include <iterator>
+#include <optional>
 #include <utility>
 
 namespace clang {
diff --git a/clang/include/clang/AST/Expr.h b/clang/include/clang/AST/Expr.h
index ed76cfa..2a81b46 100644
--- a/clang/include/clang/AST/Expr.h
+++ b/clang/include/clang/AST/Expr.h
@@ -36,6 +36,7 @@
 #include "llvm/Support/AtomicOrdering.h"
 #include "llvm/Support/Compiler.h"
 #include "llvm/Support/TrailingObjects.h"
+#include <optional>
 
 namespace clang {
   class APValue;
diff --git a/clang/include/clang/AST/ExprCXX.h b/clang/include/clang/AST/ExprCXX.h
index b754325..3851d74 100644
--- a/clang/include/clang/AST/ExprCXX.h
+++ b/clang/include/clang/AST/ExprCXX.h
@@ -51,6 +51,7 @@
 #include <cstddef>
 #include <cstdint>
 #include <memory>
+#include <optional>
 
 namespace clang {
 
diff --git a/clang/include/clang/AST/ExprObjC.h b/clang/include/clang/AST/ExprObjC.h
index 0c0629c..f1d2160 100644
--- a/clang/include/clang/AST/ExprObjC.h
+++ b/clang/include/clang/AST/ExprObjC.h
@@ -40,6 +40,7 @@
 #include <cassert>
 #include <cstddef>
 #include <cstdint>
+#include <optional>
 
 namespace clang {
 
diff --git a/clang/include/clang/AST/ExternalASTSource.h b/clang/include/clang/AST/ExternalASTSource.h
index b1851af..18f9816 100644
--- a/clang/include/clang/AST/ExternalASTSource.h
+++ b/clang/include/clang/AST/ExternalASTSource.h
@@ -30,6 +30,7 @@
 #include <cstddef>
 #include <cstdint>
 #include <iterator>
+#include <optional>
 #include <utility>
 
 namespace clang {
diff --git a/clang/include/clang/AST/FormatString.h b/clang/include/clang/AST/FormatString.h
index a2b8122..e1f8a2d 100644
--- a/clang/include/clang/AST/FormatString.h
+++ b/clang/include/clang/AST/FormatString.h
@@ -19,6 +19,7 @@
 #define LLVM_CLANG_AST_FORMATSTRING_H
 
 #include "clang/AST/CanonicalType.h"
+#include <optional>
 
 namespace clang {
 
diff --git a/clang/include/clang/AST/Mangle.h b/clang/include/clang/AST/Mangle.h
index 80e7a9d..2ed2d76 100644
--- a/clang/include/clang/AST/Mangle.h
+++ b/clang/include/clang/AST/Mangle.h
@@ -19,6 +19,7 @@
 #include "clang/Basic/ABI.h"
 #include "llvm/ADT/DenseMap.h"
 #include "llvm/Support/Casting.h"
+#include <optional>
 
 namespace llvm {
   class raw_ostream;
diff --git a/clang/include/clang/AST/NSAPI.h b/clang/include/clang/AST/NSAPI.h
index a8bd2d0..7692502 100644
--- a/clang/include/clang/AST/NSAPI.h
+++ b/clang/include/clang/AST/NSAPI.h
@@ -12,6 +12,7 @@
 #include "clang/Basic/IdentifierTable.h"
 #include "llvm/ADT/ArrayRef.h"
 #include "llvm/ADT/Optional.h"
+#include <optional>
 
 namespace clang {
   class ASTContext;
diff --git a/clang/include/clang/AST/Stmt.h b/clang/include/clang/AST/Stmt.h
index e4a6ec9..1f7b095 100644
--- a/clang/include/clang/AST/Stmt.h
+++ b/clang/include/clang/AST/Stmt.h
@@ -36,6 +36,7 @@
 #include <cassert>
 #include <cstddef>
 #include <iterator>
+#include <optional>
 #include <string>
 
 namespace llvm {
diff --git a/clang/include/clang/AST/TemplateBase.h b/clang/include/clang/AST/TemplateBase.h
index 6ba867d..d4bf4e3 100644
--- a/clang/include/clang/AST/TemplateBase.h
+++ b/clang/include/clang/AST/TemplateBase.h
@@ -30,6 +30,7 @@
 #include <cassert>
 #include <cstddef>
 #include <cstdint>
+#include <optional>
 
 namespace llvm {
 
diff --git a/clang/include/clang/AST/TemplateName.h b/clang/include/clang/AST/TemplateName.h
index d723356..c7489f6 100644
--- a/clang/include/clang/AST/TemplateName.h
+++ b/clang/include/clang/AST/TemplateName.h
@@ -21,6 +21,7 @@
 #include "llvm/ADT/PointerUnion.h"
 #include "llvm/Support/PointerLikeTypeTraits.h"
 #include <cassert>
+#include <optional>
 
 namespace clang {
 
diff --git a/clang/include/clang/AST/Type.h b/clang/include/clang/AST/Type.h
index 25d4cab..21843c3c 100644
--- a/clang/include/clang/AST/Type.h
+++ b/clang/include/clang/AST/Type.h
@@ -50,6 +50,7 @@
 #include <cstddef>
 #include <cstdint>
 #include <cstring>
+#include <optional>
 #include <string>
 #include <type_traits>
 #include <utility>
diff --git a/clang/include/clang/ASTMatchers/ASTMatchFinder.h b/clang/include/clang/ASTMatchers/ASTMatchFinder.h
index 9a1aad6..9ff3012 100644
--- a/clang/include/clang/ASTMatchers/ASTMatchFinder.h
+++ b/clang/include/clang/ASTMatchers/ASTMatchFinder.h
@@ -44,6 +44,7 @@
 #include "llvm/ADT/SmallPtrSet.h"
 #include "llvm/ADT/StringMap.h"
 #include "llvm/Support/Timer.h"
+#include <optional>
 
 namespace clang {
 
diff --git a/clang/include/clang/ASTMatchers/ASTMatchers.h b/clang/include/clang/ASTMatchers/ASTMatchers.h
index f1b858c..7dda0806 100644
--- a/clang/include/clang/ASTMatchers/ASTMatchers.h
+++ b/clang/include/clang/ASTMatchers/ASTMatchers.h
@@ -90,6 +90,7 @@
 #include <cstddef>
 #include <iterator>
 #include <limits>
+#include <optional>
 #include <string>
 #include <utility>
 #include <vector>
diff --git a/clang/include/clang/ASTMatchers/ASTMatchersInternal.h b/clang/include/clang/ASTMatchers/ASTMatchersInternal.h
index 04213dc..8252982 100644
--- a/clang/include/clang/ASTMatchers/ASTMatchersInternal.h
+++ b/clang/include/clang/ASTMatchers/ASTMatchersInternal.h
@@ -66,6 +66,7 @@
 #include <cstdint>
 #include <map>
 #include <memory>
+#include <optional>
 #include <string>
 #include <tuple>
 #include <type_traits>
diff --git a/clang/include/clang/ASTMatchers/Dynamic/Parser.h b/clang/include/clang/ASTMatchers/Dynamic/Parser.h
index 26e321c..ebe8597 100644
--- a/clang/include/clang/ASTMatchers/Dynamic/Parser.h
+++ b/clang/include/clang/ASTMatchers/Dynamic/Parser.h
@@ -42,6 +42,7 @@
 #include "llvm/ADT/Optional.h"
 #include "llvm/ADT/StringMap.h"
 #include "llvm/ADT/StringRef.h"
+#include <optional>
 #include <utility>
 #include <vector>
 
diff --git a/clang/include/clang/ASTMatchers/Dynamic/Registry.h b/clang/include/clang/ASTMatchers/Dynamic/Registry.h
index ee47469..e33e0c7 100644
--- a/clang/include/clang/ASTMatchers/Dynamic/Registry.h
+++ b/clang/include/clang/ASTMatchers/Dynamic/Registry.h
@@ -21,6 +21,7 @@
 #include "llvm/ADT/ArrayRef.h"
 #include "llvm/ADT/Optional.h"
 #include "llvm/ADT/StringRef.h"
+#include <optional>
 #include <string>
 #include <utility>
 #include <vector>
diff --git a/clang/include/clang/ASTMatchers/Dynamic/VariantValue.h b/clang/include/clang/ASTMatchers/Dynamic/VariantValue.h
index eec9255..d67d5c3 100644
--- a/clang/include/clang/ASTMatchers/Dynamic/VariantValue.h
+++ b/clang/include/clang/ASTMatchers/Dynamic/VariantValue.h
@@ -22,6 +22,7 @@
 #include "llvm/ADT/IntrusiveRefCntPtr.h"
 #include "llvm/ADT/Optional.h"
 #include <memory>
+#include <optional>
 #include <vector>
 
 namespace clang {
diff --git a/clang/include/clang/Analysis/Analyses/ThreadSafetyTIL.h b/clang/include/clang/Analysis/Analyses/ThreadSafetyTIL.h
index 6bb99f0..9c34f33 100644
--- a/clang/include/clang/Analysis/Analyses/ThreadSafetyTIL.h
+++ b/clang/include/clang/Analysis/Analyses/ThreadSafetyTIL.h
@@ -59,6 +59,7 @@
 #include <cstddef>
 #include <cstdint>
 #include <iterator>
+#include <optional>
 #include <string>
 #include <utility>
 
diff --git a/clang/include/clang/Analysis/AnyCall.h b/clang/include/clang/Analysis/AnyCall.h
index d18c046..801105b 100644
--- a/clang/include/clang/Analysis/AnyCall.h
+++ b/clang/include/clang/Analysis/AnyCall.h
@@ -16,6 +16,7 @@
 #include "clang/AST/Decl.h"
 #include "clang/AST/ExprCXX.h"
 #include "clang/AST/ExprObjC.h"
+#include <optional>
 
 namespace clang {
 
diff --git a/clang/include/clang/Analysis/BodyFarm.h b/clang/include/clang/Analysis/BodyFarm.h
index d947ac0..f6ed9d6 100644
--- a/clang/include/clang/Analysis/BodyFarm.h
+++ b/clang/include/clang/Analysis/BodyFarm.h
@@ -18,6 +18,7 @@
 #include "clang/Basic/LLVM.h"
 #include "llvm/ADT/DenseMap.h"
 #include "llvm/ADT/Optional.h"
+#include <optional>
 
 namespace clang {
 
diff --git a/clang/include/clang/Analysis/CFG.h b/clang/include/clang/Analysis/CFG.h
index c3721d0..f2cf9f9 100644
--- a/clang/include/clang/Analysis/CFG.h
+++ b/clang/include/clang/Analysis/CFG.h
@@ -31,6 +31,7 @@
 #include <cstddef>
 #include <iterator>
 #include <memory>
+#include <optional>
 #include <vector>
 
 namespace clang {
diff --git a/clang/include/clang/Analysis/FlowSensitive/DataflowAnalysis.h b/clang/include/clang/Analysis/FlowSensitive/DataflowAnalysis.h
index 62ab989..03d48ca 100644
--- a/clang/include/clang/Analysis/FlowSensitive/DataflowAnalysis.h
+++ b/clang/include/clang/Analysis/FlowSensitive/DataflowAnalysis.h
@@ -15,6 +15,7 @@
 #define LLVM_CLANG_ANALYSIS_FLOWSENSITIVE_DATAFLOWANALYSIS_H
 
 #include <iterator>
+#include <optional>
 #include <type_traits>
 #include <utility>
 #include <vector>
diff --git a/clang/include/clang/Analysis/FlowSensitive/DataflowAnalysisContext.h b/clang/include/clang/Analysis/FlowSensitive/DataflowAnalysisContext.h
index 72ddfbb..4ab1e9c 100644
--- a/clang/include/clang/Analysis/FlowSensitive/DataflowAnalysisContext.h
+++ b/clang/include/clang/Analysis/FlowSensitive/DataflowAnalysisContext.h
@@ -27,6 +27,7 @@
 #include "llvm/Support/Compiler.h"
 #include <cassert>
 #include <memory>
+#include <optional>
 #include <type_traits>
 #include <utility>
 #include <vector>
diff --git a/clang/include/clang/Analysis/FlowSensitive/Solver.h b/clang/include/clang/Analysis/FlowSensitive/Solver.h
index 93568b1..d0f954d 100644
--- a/clang/include/clang/Analysis/FlowSensitive/Solver.h
+++ b/clang/include/clang/Analysis/FlowSensitive/Solver.h
@@ -18,6 +18,7 @@
 #include "llvm/ADT/DenseMap.h"
 #include "llvm/ADT/DenseSet.h"
 #include "llvm/ADT/Optional.h"
+#include <optional>
 
 namespace clang {
 namespace dataflow {
diff --git a/clang/include/clang/Analysis/FlowSensitive/TypeErasedDataflowAnalysis.h b/clang/include/clang/Analysis/FlowSensitive/TypeErasedDataflowAnalysis.h
index 05e958c..ab04a70 100644
--- a/clang/include/clang/Analysis/FlowSensitive/TypeErasedDataflowAnalysis.h
+++ b/clang/include/clang/Analysis/FlowSensitive/TypeErasedDataflowAnalysis.h
@@ -14,6 +14,7 @@
 #ifndef LLVM_CLANG_ANALYSIS_FLOWSENSITIVE_TYPEERASEDDATAFLOWANALYSIS_H
 #define LLVM_CLANG_ANALYSIS_FLOWSENSITIVE_TYPEERASEDDATAFLOWANALYSIS_H
 
+#include <optional>
 #include <utility>
 #include <vector>
 
diff --git a/clang/include/clang/Analysis/MacroExpansionContext.h b/clang/include/clang/Analysis/MacroExpansionContext.h
index ea9ced0..bfa529f 100644
--- a/clang/include/clang/Analysis/MacroExpansionContext.h
+++ b/clang/include/clang/Analysis/MacroExpansionContext.h
@@ -16,6 +16,7 @@
 #include "llvm/ADT/Optional.h"
 #include "llvm/ADT/SmallString.h"
 #include "llvm/ADT/SmallVector.h"
+#include <optional>
 
 namespace clang {
 
diff --git a/clang/include/clang/Analysis/PathDiagnostic.h b/clang/include/clang/Analysis/PathDiagnostic.h
index 342053a..e6c7173 100644
--- a/clang/include/clang/Analysis/PathDiagnostic.h
+++ b/clang/include/clang/Analysis/PathDiagnostic.h
@@ -30,6 +30,7 @@
 #include <list>
 #include <map>
 #include <memory>
+#include <optional>
 #include <set>
 #include <string>
 #include <utility>
diff --git a/clang/include/clang/Analysis/ProgramPoint.h b/clang/include/clang/Analysis/ProgramPoint.h
index 1df5b74..2478137 100644
--- a/clang/include/clang/Analysis/ProgramPoint.h
+++ b/clang/include/clang/Analysis/ProgramPoint.h
@@ -24,6 +24,7 @@
 #include "llvm/Support/Casting.h"
 #include "llvm/Support/DataTypes.h"
 #include <cassert>
+#include <optional>
 #include <string>
 #include <utility>
 
diff --git a/clang/include/clang/Analysis/RetainSummaryManager.h b/clang/include/clang/Analysis/RetainSummaryManager.h
index 3171dc3..58129df 100644
--- a/clang/include/clang/Analysis/RetainSummaryManager.h
+++ b/clang/include/clang/Analysis/RetainSummaryManager.h
@@ -25,6 +25,7 @@
 #include "clang/Analysis/AnyCall.h"
 #include "clang/Analysis/SelectorExtras.h"
 #include "llvm/ADT/STLExtras.h"
+#include <optional>
 
 using namespace clang;
 
diff --git a/clang/include/clang/Basic/DarwinSDKInfo.h b/clang/include/clang/Basic/DarwinSDKInfo.h
index 6a13ddd..7a44187 100644
--- a/clang/include/clang/Basic/DarwinSDKInfo.h
+++ b/clang/include/clang/Basic/DarwinSDKInfo.h
@@ -15,6 +15,7 @@
 #include "llvm/Support/Error.h"
 #include "llvm/Support/VersionTuple.h"
 #include "llvm/Support/VirtualFileSystem.h"
+#include <optional>
 
 namespace llvm {
 namespace json {
diff --git a/clang/include/clang/Basic/Diagnostic.h b/clang/include/clang/Basic/Diagnostic.h
index 927ed14..9b5272e 100644
--- a/clang/include/clang/Basic/Diagnostic.h
+++ b/clang/include/clang/Basic/Diagnostic.h
@@ -32,6 +32,7 @@
 #include <list>
 #include <map>
 #include <memory>
+#include <optional>
 #include <string>
 #include <type_traits>
 #include <utility>
diff --git a/clang/include/clang/Basic/DiagnosticError.h b/clang/include/clang/Basic/DiagnosticError.h
index 76d893a..a42329b 100644
--- a/clang/include/clang/Basic/DiagnosticError.h
+++ b/clang/include/clang/Basic/DiagnosticError.h
@@ -11,6 +11,7 @@
 
 #include "clang/Basic/PartialDiagnostic.h"
 #include "llvm/Support/Error.h"
+#include <optional>
 
 namespace clang {
 
diff --git a/clang/include/clang/Basic/DiagnosticIDs.h b/clang/include/clang/Basic/DiagnosticIDs.h
index 91b180f..3211dba 100644
--- a/clang/include/clang/Basic/DiagnosticIDs.h
+++ b/clang/include/clang/Basic/DiagnosticIDs.h
@@ -17,6 +17,7 @@
 #include "clang/Basic/LLVM.h"
 #include "llvm/ADT/IntrusiveRefCntPtr.h"
 #include "llvm/ADT/StringRef.h"
+#include <optional>
 #include <vector>
 
 namespace clang {
diff --git a/clang/include/clang/Basic/DirectoryEntry.h b/clang/include/clang/Basic/DirectoryEntry.h
index dca68ef..6c8da12 100644
--- a/clang/include/clang/Basic/DirectoryEntry.h
+++ b/clang/include/clang/Basic/DirectoryEntry.h
@@ -23,6 +23,7 @@
 #include "llvm/ADT/StringRef.h"
 #include "llvm/Support/ErrorOr.h"
 
+#include <optional>
 #include <utility>
 
 namespace clang {
diff --git a/clang/include/clang/Basic/FileEntry.h b/clang/include/clang/Basic/FileEntry.h
index 6ff9c19a..93e84cf 100644
--- a/clang/include/clang/Basic/FileEntry.h
+++ b/clang/include/clang/Basic/FileEntry.h
@@ -25,6 +25,7 @@
 #include "llvm/Support/ErrorOr.h"
 #include "llvm/Support/FileSystem/UniqueID.h"
 
+#include <optional>
 #include <utility>
 
 namespace llvm {
diff --git a/clang/include/clang/Basic/FileSystemStatCache.h b/clang/include/clang/Basic/FileSystemStatCache.h
index d37f2d5..e9f9fa3 100644
--- a/clang/include/clang/Basic/FileSystemStatCache.h
+++ b/clang/include/clang/Basic/FileSystemStatCache.h
@@ -23,6 +23,7 @@
 #include <cstdint>
 #include <ctime>
 #include <memory>
+#include <optional>
 #include <string>
 #include <utility>
 
diff --git a/clang/include/clang/Basic/LangOptions.h b/clang/include/clang/Basic/LangOptions.h
index 41b0426..47d04f3 100644
--- a/clang/include/clang/Basic/LangOptions.h
+++ b/clang/include/clang/Basic/LangOptions.h
@@ -24,6 +24,7 @@
 #include "llvm/ADT/FloatingPointMode.h"
 #include "llvm/ADT/StringRef.h"
 #include "llvm/ADT/Triple.h"
+#include <optional>
 #include <string>
 #include <vector>
 
diff --git a/clang/include/clang/Basic/Module.h b/clang/include/clang/Basic/Module.h
index 11c021e..cb430d5 100644
--- a/clang/include/clang/Basic/Module.h
+++ b/clang/include/clang/Basic/Module.h
@@ -33,6 +33,7 @@
 #include <cstdint>
 #include <ctime>
 #include <iterator>
+#include <optional>
 #include <string>
 #include <utility>
 #include <vector>
diff --git a/clang/include/clang/Basic/ProfileList.h b/clang/include/clang/Basic/ProfileList.h
index f776800..23829bd 100644
--- a/clang/include/clang/Basic/ProfileList.h
+++ b/clang/include/clang/Basic/ProfileList.h
@@ -20,6 +20,7 @@
 #include "llvm/ADT/Optional.h"
 #include "llvm/ADT/StringRef.h"
 #include <memory>
+#include <optional>
 
 namespace clang {
 
diff --git a/clang/include/clang/Basic/Sarif.h b/clang/include/clang/Basic/Sarif.h
index d76b9d1..9fbe70e 100644
--- a/clang/include/clang/Basic/Sarif.h
+++ b/clang/include/clang/Basic/Sarif.h
@@ -43,6 +43,7 @@
 #include <cstddef>
 #include <cstdint>
 #include <initializer_list>
+#include <optional>
 #include <string>
 
 namespace clang {
diff --git a/clang/include/clang/Basic/SourceManager.h b/clang/include/clang/Basic/SourceManager.h
index d7f8125..27c8fe8 100644
--- a/clang/include/clang/Basic/SourceManager.h
+++ b/clang/include/clang/Basic/SourceManager.h
@@ -53,6 +53,7 @@
 #include <cstddef>
 #include <map>
 #include <memory>
+#include <optional>
 #include <string>
 #include <utility>
 #include <vector>
diff --git a/clang/include/clang/CrossTU/CrossTranslationUnit.h b/clang/include/clang/CrossTU/CrossTranslationUnit.h
index 47b48ce..5002c1c 100644
--- a/clang/include/clang/CrossTU/CrossTranslationUnit.h
+++ b/clang/include/clang/CrossTU/CrossTranslationUnit.h
@@ -23,6 +23,7 @@
 #include "llvm/ADT/StringMap.h"
 #include "llvm/Support/Error.h"
 #include "llvm/Support/Path.h"
+#include <optional>
 
 namespace clang {
 class CompilerInstance;
diff --git a/clang/include/clang/ExtractAPI/Serialization/SymbolGraphSerializer.h b/clang/include/clang/ExtractAPI/Serialization/SymbolGraphSerializer.h
index 9bf6083..e6c1866 100644
--- a/clang/include/clang/ExtractAPI/Serialization/SymbolGraphSerializer.h
+++ b/clang/include/clang/ExtractAPI/Serialization/SymbolGraphSerializer.h
@@ -24,6 +24,7 @@
 #include "llvm/Support/JSON.h"
 #include "llvm/Support/VersionTuple.h"
 #include "llvm/Support/raw_ostream.h"
+#include <optional>
 
 namespace clang {
 namespace extractapi {
diff --git a/clang/include/clang/Format/Format.h b/clang/include/clang/Format/Format.h
index 36472c6..c5bfbfe 100644
--- a/clang/include/clang/Format/Format.h
+++ b/clang/include/clang/Format/Format.h
@@ -20,6 +20,7 @@
 #include "llvm/ADT/ArrayRef.h"
 #include "llvm/Support/Regex.h"
 #include "llvm/Support/SourceMgr.h"
+#include <optional>
 #include <system_error>
 
 namespace llvm {
diff --git a/clang/include/clang/Frontend/ASTUnit.h b/clang/include/clang/Frontend/ASTUnit.h
index c87e143..62c0190 100644
--- a/clang/include/clang/Frontend/ASTUnit.h
+++ b/clang/include/clang/Frontend/ASTUnit.h
@@ -41,6 +41,7 @@
 #include <cstddef>
 #include <cstdint>
 #include <memory>
+#include <optional>
 #include <string>
 #include <utility>
 #include <vector>
diff --git a/clang/include/clang/Frontend/CommandLineSourceLoc.h b/clang/include/clang/Frontend/CommandLineSourceLoc.h
index f511475..4637a1c 100644
--- a/clang/include/clang/Frontend/CommandLineSourceLoc.h
+++ b/clang/include/clang/Frontend/CommandLineSourceLoc.h
@@ -17,6 +17,7 @@
 #include "clang/Basic/LLVM.h"
 #include "llvm/Support/CommandLine.h"
 #include "llvm/Support/raw_ostream.h"
+#include <optional>
 
 namespace clang {
 
diff --git a/clang/include/clang/Frontend/CompilerInstance.h b/clang/include/clang/Frontend/CompilerInstance.h
index 577daad..04d32c2 100644
--- a/clang/include/clang/Frontend/CompilerInstance.h
+++ b/clang/include/clang/Frontend/CompilerInstance.h
@@ -26,6 +26,7 @@
 #include <cassert>
 #include <list>
 #include <memory>
+#include <optional>
 #include <string>
 #include <utility>
 
diff --git a/clang/include/clang/Frontend/FrontendOptions.h b/clang/include/clang/Frontend/FrontendOptions.h
index 9183fcb..a757749 100644
--- a/clang/include/clang/Frontend/FrontendOptions.h
+++ b/clang/include/clang/Frontend/FrontendOptions.h
@@ -19,6 +19,7 @@
 #include <cassert>
 #include <map>
 #include <memory>
+#include <optional>
 #include <string>
 #include <vector>
 
diff --git a/clang/include/clang/Lex/HeaderMap.h b/clang/include/clang/Lex/HeaderMap.h
index 2a4af28..9836765 100644
--- a/clang/include/clang/Lex/HeaderMap.h
+++ b/clang/include/clang/Lex/HeaderMap.h
@@ -21,6 +21,7 @@
 #include "llvm/Support/Compiler.h"
 #include "llvm/Support/MemoryBuffer.h"
 #include <memory>
+#include <optional>
 
 namespace clang {
 
diff --git a/clang/include/clang/Lex/Lexer.h b/clang/include/clang/Lex/Lexer.h
index 35c6a7b..3e21987 100644
--- a/clang/include/clang/Lex/Lexer.h
+++ b/clang/include/clang/Lex/Lexer.h
@@ -24,6 +24,7 @@
 #include "llvm/ADT/StringRef.h"
 #include <cassert>
 #include <cstdint>
+#include <optional>
 #include <string>
 
 namespace llvm {
diff --git a/clang/include/clang/Lex/ModuleMap.h b/clang/include/clang/Lex/ModuleMap.h
index ba7b681..2ce5961 100644
--- a/clang/include/clang/Lex/ModuleMap.h
+++ b/clang/include/clang/Lex/ModuleMap.h
@@ -30,6 +30,7 @@
 #include "llvm/ADT/Twine.h"
 #include <ctime>
 #include <memory>
+#include <optional>
 #include <string>
 #include <utility>
 
diff --git a/clang/include/clang/Lex/PreprocessingRecord.h b/clang/include/clang/Lex/PreprocessingRecord.h
index c385bc6..fd269fd 100644
--- a/clang/include/clang/Lex/PreprocessingRecord.h
+++ b/clang/include/clang/Lex/PreprocessingRecord.h
@@ -29,6 +29,7 @@
 #include <cassert>
 #include <cstddef>
 #include <iterator>
+#include <optional>
 #include <utility>
 #include <vector>
 
diff --git a/clang/include/clang/Lex/Preprocessor.h b/clang/include/clang/Lex/Preprocessor.h
index b39eca9..afef702 100644
--- a/clang/include/clang/Lex/Preprocessor.h
+++ b/clang/include/clang/Lex/Preprocessor.h
@@ -51,6 +51,7 @@
 #include <cstdint>
 #include <map>
 #include <memory>
+#include <optional>
 #include <string>
 #include <utility>
 #include <vector>
diff --git a/clang/include/clang/Lex/PreprocessorOptions.h b/clang/include/clang/Lex/PreprocessorOptions.h
index d51f2bcb..8ad2cc2 100644
--- a/clang/include/clang/Lex/PreprocessorOptions.h
+++ b/clang/include/clang/Lex/PreprocessorOptions.h
@@ -18,6 +18,7 @@
 #include <functional>
 #include <map>
 #include <memory>
+#include <optional>
 #include <set>
 #include <string>
 #include <utility>
diff --git a/clang/include/clang/Parse/Parser.h b/clang/include/clang/Parse/Parser.h
index 8d934d5..4f87d55 100644
--- a/clang/include/clang/Parse/Parser.h
+++ b/clang/include/clang/Parse/Parser.h
@@ -28,6 +28,7 @@
 #include "llvm/Support/PrettyStackTrace.h"
 #include "llvm/Support/SaveAndRestore.h"
 #include <memory>
+#include <optional>
 #include <stack>
 
 namespace clang {
diff --git a/clang/include/clang/Sema/CodeCompleteConsumer.h b/clang/include/clang/Sema/CodeCompleteConsumer.h
index 814201a..063c960 100644
--- a/clang/include/clang/Sema/CodeCompleteConsumer.h
+++ b/clang/include/clang/Sema/CodeCompleteConsumer.h
@@ -29,6 +29,7 @@
 #include "llvm/Support/type_traits.h"
 #include <cassert>
 #include <memory>
+#include <optional>
 #include <string>
 #include <utility>
 
diff --git a/clang/include/clang/Sema/Lookup.h b/clang/include/clang/Sema/Lookup.h
index 8b11273..34a8756 100644
--- a/clang/include/clang/Sema/Lookup.h
+++ b/clang/include/clang/Sema/Lookup.h
@@ -30,6 +30,7 @@
 #include "llvm/ADT/STLExtras.h"
 #include "llvm/Support/Casting.h"
 #include <cassert>
+#include <optional>
 #include <utility>
 
 namespace clang {
diff --git a/clang/include/clang/Sema/Scope.h b/clang/include/clang/Sema/Scope.h
index caeef06..7290879 100644
--- a/clang/include/clang/Sema/Scope.h
+++ b/clang/include/clang/Sema/Scope.h
@@ -20,6 +20,7 @@
 #include "llvm/ADT/SmallVector.h"
 #include "llvm/ADT/iterator_range.h"
 #include <cassert>
+#include <optional>
 
 namespace llvm {
 
diff --git a/clang/include/clang/Sema/Sema.h b/clang/include/clang/Sema/Sema.h
index be5265b..33d8ed6 100644
--- a/clang/include/clang/Sema/Sema.h
+++ b/clang/include/clang/Sema/Sema.h
@@ -68,6 +68,7 @@
 #include "llvm/Frontend/OpenMP/OMPConstants.h"
 #include <deque>
 #include <memory>
+#include <optional>
 #include <string>
 #include <tuple>
 #include <vector>
diff --git a/clang/include/clang/Sema/SemaConcept.h b/clang/include/clang/Sema/SemaConcept.h
index a5b65f2..1cbe18f 100644
--- a/clang/include/clang/Sema/SemaConcept.h
+++ b/clang/include/clang/Sema/SemaConcept.h
@@ -20,6 +20,7 @@
 #include "llvm/ADT/PointerUnion.h"
 #include "llvm/ADT/Optional.h"
 #include "llvm/ADT/SmallVector.h"
+#include <optional>
 #include <string>
 #include <utility>
 
diff --git a/clang/include/clang/Sema/SemaLambda.h b/clang/include/clang/Sema/SemaLambda.h
index 4945687..fcc4ebe 100644
--- a/clang/include/clang/Sema/SemaLambda.h
+++ b/clang/include/clang/Sema/SemaLambda.h
@@ -16,6 +16,7 @@
 #define LLVM_CLANG_SEMA_SEMALAMBDA_H
 
 #include "clang/AST/ASTLambda.h"
+#include <optional>
 
 namespace clang {
 namespace sema {
diff --git a/clang/include/clang/Sema/Template.h b/clang/include/clang/Sema/Template.h
index 8f3657d..52fff8e 100644
--- a/clang/include/clang/Sema/Template.h
+++ b/clang/include/clang/Sema/Template.h
@@ -23,6 +23,7 @@
 #include "llvm/ADT/PointerUnion.h"
 #include "llvm/ADT/SmallVector.h"
 #include <cassert>
+#include <optional>
 #include <utility>
 
 namespace clang {
diff --git a/clang/include/clang/Sema/TemplateDeduction.h b/clang/include/clang/Sema/TemplateDeduction.h
index ba35a5a..e8d235c 100644
--- a/clang/include/clang/Sema/TemplateDeduction.h
+++ b/clang/include/clang/Sema/TemplateDeduction.h
@@ -26,6 +26,7 @@
 #include "llvm/ADT/SmallVector.h"
 #include <cassert>
 #include <cstddef>
+#include <optional>
 #include <utility>
 
 namespace clang {
diff --git a/clang/include/clang/Serialization/ASTReader.h b/clang/include/clang/Serialization/ASTReader.h
index 1b9b12c..f2a7f26 100644
--- a/clang/include/clang/Serialization/ASTReader.h
+++ b/clang/include/clang/Serialization/ASTReader.h
@@ -57,6 +57,7 @@
 #include <ctime>
 #include <deque>
 #include <memory>
+#include <optional>
 #include <set>
 #include <string>
 #include <utility>
diff --git a/clang/include/clang/StaticAnalyzer/Core/BugReporter/BugReporter.h b/clang/include/clang/StaticAnalyzer/Core/BugReporter/BugReporter.h
index 78bc467..d89eaf50 100644
--- a/clang/include/clang/StaticAnalyzer/Core/BugReporter/BugReporter.h
+++ b/clang/include/clang/StaticAnalyzer/Core/BugReporter/BugReporter.h
@@ -38,6 +38,7 @@
 #include "llvm/ADT/iterator_range.h"
 #include <cassert>
 #include <memory>
+#include <optional>
 #include <string>
 #include <utility>
 #include <vector>
diff --git a/clang/include/clang/StaticAnalyzer/Core/BugReporter/BugReporterVisitors.h b/clang/include/clang/StaticAnalyzer/Core/BugReporter/BugReporterVisitors.h
index 48da56c..6ccae6f 100644
--- a/clang/include/clang/StaticAnalyzer/Core/BugReporter/BugReporterVisitors.h
+++ b/clang/include/clang/StaticAnalyzer/Core/BugReporter/BugReporterVisitors.h
@@ -25,6 +25,7 @@
 #include "llvm/ADT/StringRef.h"
 #include <list>
 #include <memory>
+#include <optional>
 #include <utility>
 
 namespace clang {
diff --git a/clang/include/clang/StaticAnalyzer/Core/PathSensitive/CallDescription.h b/clang/include/clang/StaticAnalyzer/Core/PathSensitive/CallDescription.h
index 091c3ce..360f81e 100644
--- a/clang/include/clang/StaticAnalyzer/Core/PathSensitive/CallDescription.h
+++ b/clang/include/clang/StaticAnalyzer/Core/PathSensitive/CallDescription.h
@@ -19,6 +19,7 @@
 #include "llvm/ADT/ArrayRef.h"
 #include "llvm/ADT/Optional.h"
 #include "llvm/Support/Compiler.h"
+#include <optional>
 #include <vector>
 
 namespace clang {
diff --git a/clang/include/clang/StaticAnalyzer/Core/PathSensitive/CallEvent.h b/clang/include/clang/StaticAnalyzer/Core/PathSensitive/CallEvent.h
index 7394a7d..6ac768c 100644
--- a/clang/include/clang/StaticAnalyzer/Core/PathSensitive/CallEvent.h
+++ b/clang/include/clang/StaticAnalyzer/Core/PathSensitive/CallEvent.h
@@ -45,6 +45,7 @@
 #include "llvm/Support/ErrorHandling.h"
 #include <cassert>
 #include <limits>
+#include <optional>
 #include <utility>
 
 namespace clang {
diff --git a/clang/include/clang/StaticAnalyzer/Core/PathSensitive/CheckerContext.h b/clang/include/clang/StaticAnalyzer/Core/PathSensitive/CheckerContext.h
index a40d883..ce1407e 100644
--- a/clang/include/clang/StaticAnalyzer/Core/PathSensitive/CheckerContext.h
+++ b/clang/include/clang/StaticAnalyzer/Core/PathSensitive/CheckerContext.h
@@ -16,6 +16,7 @@
 
 #include "clang/StaticAnalyzer/Core/PathSensitive/ExprEngine.h"
 #include "clang/StaticAnalyzer/Core/PathSensitive/ProgramStateTrait.h"
+#include <optional>
 
 namespace clang {
 namespace ento {
diff --git a/clang/include/clang/StaticAnalyzer/Core/PathSensitive/CheckerHelpers.h b/clang/include/clang/StaticAnalyzer/Core/PathSensitive/CheckerHelpers.h
index f7a39e7..2ad5e1f8 100644
--- a/clang/include/clang/StaticAnalyzer/Core/PathSensitive/CheckerHelpers.h
+++ b/clang/include/clang/StaticAnalyzer/Core/PathSensitive/CheckerHelpers.h
@@ -17,6 +17,7 @@
 #include "clang/AST/Stmt.h"
 #include "clang/Basic/OperatorKinds.h"
 #include "llvm/ADT/Optional.h"
+#include <optional>
 #include <tuple>
 
 namespace clang {
diff --git a/clang/include/clang/StaticAnalyzer/Core/PathSensitive/ConstraintManager.h b/clang/include/clang/StaticAnalyzer/Core/PathSensitive/ConstraintManager.h
index 92df266..eb84506 100644
--- a/clang/include/clang/StaticAnalyzer/Core/PathSensitive/ConstraintManager.h
+++ b/clang/include/clang/StaticAnalyzer/Core/PathSensitive/ConstraintManager.h
@@ -20,6 +20,7 @@
 #include "llvm/ADT/Optional.h"
 #include "llvm/Support/SaveAndRestore.h"
 #include <memory>
+#include <optional>
 #include <utility>
 
 namespace llvm {
diff --git a/clang/include/clang/StaticAnalyzer/Core/PathSensitive/ExplodedGraph.h b/clang/include/clang/StaticAnalyzer/Core/PathSensitive/ExplodedGraph.h
index faabd48..5b7e337 100644
--- a/clang/include/clang/StaticAnalyzer/Core/PathSensitive/ExplodedGraph.h
+++ b/clang/include/clang/StaticAnalyzer/Core/PathSensitive/ExplodedGraph.h
@@ -38,6 +38,7 @@
 #include <cassert>
 #include <cstdint>
 #include <memory>
+#include <optional>
 #include <utility>
 #include <vector>
 
diff --git a/clang/include/clang/StaticAnalyzer/Core/PathSensitive/ExprEngine.h b/clang/include/clang/StaticAnalyzer/Core/PathSensitive/ExprEngine.h
index dd1b755..a5e075c 100644
--- a/clang/include/clang/StaticAnalyzer/Core/PathSensitive/ExprEngine.h
+++ b/clang/include/clang/StaticAnalyzer/Core/PathSensitive/ExprEngine.h
@@ -36,6 +36,7 @@
 #include "clang/StaticAnalyzer/Core/PathSensitive/WorkList.h"
 #include "llvm/ADT/ArrayRef.h"
 #include <cassert>
+#include <optional>
 #include <utility>
 
 namespace clang {
diff --git a/clang/include/clang/StaticAnalyzer/Core/PathSensitive/FunctionSummary.h b/clang/include/clang/StaticAnalyzer/Core/PathSensitive/FunctionSummary.h
index 5359fea..effe9e4 100644
--- a/clang/include/clang/StaticAnalyzer/Core/PathSensitive/FunctionSummary.h
+++ b/clang/include/clang/StaticAnalyzer/Core/PathSensitive/FunctionSummary.h
@@ -21,6 +21,7 @@
 #include "llvm/ADT/SmallBitVector.h"
 #include <cassert>
 #include <deque>
+#include <optional>
 #include <utility>
 
 namespace clang {
diff --git a/clang/include/clang/StaticAnalyzer/Core/PathSensitive/MemRegion.h b/clang/include/clang/StaticAnalyzer/Core/PathSensitive/MemRegion.h
index aa21ef2..7455112 100644
--- a/clang/include/clang/StaticAnalyzer/Core/PathSensitive/MemRegion.h
+++ b/clang/include/clang/StaticAnalyzer/Core/PathSensitive/MemRegion.h
@@ -37,6 +37,7 @@
 #include <cassert>
 #include <cstdint>
 #include <limits>
+#include <optional>
 #include <string>
 #include <utility>
 
diff --git a/clang/include/clang/StaticAnalyzer/Core/PathSensitive/ProgramState.h b/clang/include/clang/StaticAnalyzer/Core/PathSensitive/ProgramState.h
index cdb6d8f..0e37182 100644
--- a/clang/include/clang/StaticAnalyzer/Core/PathSensitive/ProgramState.h
+++ b/clang/include/clang/StaticAnalyzer/Core/PathSensitive/ProgramState.h
@@ -23,6 +23,7 @@
 #include "llvm/ADT/FoldingSet.h"
 #include "llvm/ADT/ImmutableMap.h"
 #include "llvm/Support/Allocator.h"
+#include <optional>
 #include <utility>
 
 namespace llvm {
diff --git a/clang/include/clang/StaticAnalyzer/Core/PathSensitive/SMTConstraintManager.h b/clang/include/clang/StaticAnalyzer/Core/PathSensitive/SMTConstraintManager.h
index 7bbb4c6..d00432d 100644
--- a/clang/include/clang/StaticAnalyzer/Core/PathSensitive/SMTConstraintManager.h
+++ b/clang/include/clang/StaticAnalyzer/Core/PathSensitive/SMTConstraintManager.h
@@ -18,6 +18,7 @@
 #include "clang/Basic/TargetInfo.h"
 #include "clang/StaticAnalyzer/Core/PathSensitive/RangedConstraintManager.h"
 #include "clang/StaticAnalyzer/Core/PathSensitive/SMTConv.h"
+#include <optional>
 
 typedef llvm::ImmutableSet<
     std::pair<clang::ento::SymbolRef, const llvm::SMTExpr *>>
diff --git a/clang/include/clang/StaticAnalyzer/Core/PathSensitive/SValBuilder.h b/clang/include/clang/StaticAnalyzer/Core/PathSensitive/SValBuilder.h
index adc3af9..298435f 100644
--- a/clang/include/clang/StaticAnalyzer/Core/PathSensitive/SValBuilder.h
+++ b/clang/include/clang/StaticAnalyzer/Core/PathSensitive/SValBuilder.h
@@ -30,6 +30,7 @@
 #include "llvm/ADT/ImmutableList.h"
 #include "llvm/ADT/Optional.h"
 #include <cstdint>
+#include <optional>
 
 namespace clang {
 
diff --git a/clang/include/clang/StaticAnalyzer/Core/PathSensitive/SVals.h b/clang/include/clang/StaticAnalyzer/Core/PathSensitive/SVals.h
index 328d950..2e4afb2 100644
--- a/clang/include/clang/StaticAnalyzer/Core/PathSensitive/SVals.h
+++ b/clang/include/clang/StaticAnalyzer/Core/PathSensitive/SVals.h
@@ -25,6 +25,7 @@
 #include "llvm/Support/Casting.h"
 #include <cassert>
 #include <cstdint>
+#include <optional>
 #include <utility>
 
 //==------------------------------------------------------------------------==//
diff --git a/clang/include/clang/StaticAnalyzer/Core/PathSensitive/Store.h b/clang/include/clang/StaticAnalyzer/Core/PathSensitive/Store.h
index 80db6bf..bf2dfd1 100644
--- a/clang/include/clang/StaticAnalyzer/Core/PathSensitive/Store.h
+++ b/clang/include/clang/StaticAnalyzer/Core/PathSensitive/Store.h
@@ -28,6 +28,7 @@
 #include <cassert>
 #include <cstdint>
 #include <memory>
+#include <optional>
 
 namespace clang {
 
diff --git a/clang/include/clang/Tooling/ASTDiff/ASTDiff.h b/clang/include/clang/Tooling/ASTDiff/ASTDiff.h
index 5fe6db6..a84444a 100644
--- a/clang/include/clang/Tooling/ASTDiff/ASTDiff.h
+++ b/clang/include/clang/Tooling/ASTDiff/ASTDiff.h
@@ -20,6 +20,7 @@
 #define LLVM_CLANG_TOOLING_ASTDIFF_ASTDIFF_H
 
 #include "clang/Tooling/ASTDiff/ASTDiffInternal.h"
+#include <optional>
 
 namespace clang {
 namespace diff {
diff --git a/clang/include/clang/Tooling/AllTUsExecution.h b/clang/include/clang/Tooling/AllTUsExecution.h
index 43f2792..fcc952f 100644
--- a/clang/include/clang/Tooling/AllTUsExecution.h
+++ b/clang/include/clang/Tooling/AllTUsExecution.h
@@ -16,6 +16,7 @@
 
 #include "clang/Tooling/ArgumentsAdjusters.h"
 #include "clang/Tooling/Execution.h"
+#include <optional>
 
 namespace clang {
 namespace tooling {
diff --git a/clang/include/clang/Tooling/Core/Replacement.h b/clang/include/clang/Tooling/Core/Replacement.h
index 2c4fb8f..929d6197 100644
--- a/clang/include/clang/Tooling/Core/Replacement.h
+++ b/clang/include/clang/Tooling/Core/Replacement.h
@@ -26,6 +26,7 @@
 #include "llvm/Support/Error.h"
 #include "llvm/Support/raw_ostream.h"
 #include <map>
+#include <optional>
 #include <set>
 #include <string>
 #include <system_error>
diff --git a/clang/include/clang/Tooling/DependencyScanning/DependencyScanningFilesystem.h b/clang/include/clang/Tooling/DependencyScanning/DependencyScanningFilesystem.h
index 8f820f2..510c41f 100644
--- a/clang/include/clang/Tooling/DependencyScanning/DependencyScanningFilesystem.h
+++ b/clang/include/clang/Tooling/DependencyScanning/DependencyScanningFilesystem.h
@@ -17,6 +17,7 @@
 #include "llvm/Support/ErrorOr.h"
 #include "llvm/Support/VirtualFileSystem.h"
 #include <mutex>
+#include <optional>
 
 namespace clang {
 namespace tooling {
diff --git a/clang/include/clang/Tooling/DependencyScanning/DependencyScanningTool.h b/clang/include/clang/Tooling/DependencyScanning/DependencyScanningTool.h
index f191ea1..7262ac8 100644
--- a/clang/include/clang/Tooling/DependencyScanning/DependencyScanningTool.h
+++ b/clang/include/clang/Tooling/DependencyScanning/DependencyScanningTool.h
@@ -16,6 +16,7 @@
 #include "llvm/ADT/MapVector.h"
 #include "llvm/ADT/StringSet.h"
 #include "llvm/ADT/StringMap.h"
+#include <optional>
 #include <string>
 #include <vector>
 
diff --git a/clang/include/clang/Tooling/DependencyScanning/DependencyScanningWorker.h b/clang/include/clang/Tooling/DependencyScanning/DependencyScanningWorker.h
index 36ac2e3..7163893 100644
--- a/clang/include/clang/Tooling/DependencyScanning/DependencyScanningWorker.h
+++ b/clang/include/clang/Tooling/DependencyScanning/DependencyScanningWorker.h
@@ -17,6 +17,7 @@
 #include "clang/Tooling/DependencyScanning/ModuleDepCollector.h"
 #include "llvm/Support/Error.h"
 #include "llvm/Support/FileSystem.h"
+#include <optional>
 #include <string>
 
 namespace clang {
diff --git a/clang/include/clang/Tooling/Inclusions/HeaderIncludes.h b/clang/include/clang/Tooling/Inclusions/HeaderIncludes.h
index 1466327..e7cc1ee 100644
--- a/clang/include/clang/Tooling/Inclusions/HeaderIncludes.h
+++ b/clang/include/clang/Tooling/Inclusions/HeaderIncludes.h
@@ -15,6 +15,7 @@
 #include "llvm/Support/Path.h"
 #include "llvm/Support/Regex.h"
 #include <list>
+#include <optional>
 #include <unordered_map>
 
 namespace clang {
diff --git a/clang/include/clang/Tooling/Refactoring/ASTSelection.h b/clang/include/clang/Tooling/Refactoring/ASTSelection.h
index c07f8a8..d9e7c1b 100644
--- a/clang/include/clang/Tooling/Refactoring/ASTSelection.h
+++ b/clang/include/clang/Tooling/Refactoring/ASTSelection.h
@@ -14,6 +14,7 @@
 #include "clang/Basic/LLVM.h"
 #include "clang/Basic/SourceLocation.h"
 #include "llvm/Support/raw_ostream.h"
+#include <optional>
 #include <vector>
 
 namespace clang {
diff --git a/clang/include/clang/Tooling/Refactoring/Extract/Extract.h b/clang/include/clang/Tooling/Refactoring/Extract/Extract.h
index e3a8a0d..f72d619 100644
--- a/clang/include/clang/Tooling/Refactoring/Extract/Extract.h
+++ b/clang/include/clang/Tooling/Refactoring/Extract/Extract.h
@@ -11,6 +11,7 @@
 
 #include "clang/Tooling/Refactoring/ASTSelection.h"
 #include "clang/Tooling/Refactoring/RefactoringActionRules.h"
+#include <optional>
 
 namespace clang {
 namespace tooling {
diff --git a/clang/include/clang/Tooling/Refactoring/RefactoringOptionVisitor.h b/clang/include/clang/Tooling/Refactoring/RefactoringOptionVisitor.h
index f9f85f6..327f470 100644
--- a/clang/include/clang/Tooling/Refactoring/RefactoringOptionVisitor.h
+++ b/clang/include/clang/Tooling/Refactoring/RefactoringOptionVisitor.h
@@ -10,6 +10,7 @@
 #define LLVM_CLANG_TOOLING_REFACTORING_REFACTORINGOPTIONVISITOR_H
 
 #include "clang/Basic/LLVM.h"
+#include <optional>
 #include <type_traits>
 
 namespace clang {
diff --git a/clang/include/clang/Tooling/Refactoring/RefactoringOptions.h b/clang/include/clang/Tooling/Refactoring/RefactoringOptions.h
index 75bd91d..963eb2d 100644
--- a/clang/include/clang/Tooling/Refactoring/RefactoringOptions.h
+++ b/clang/include/clang/Tooling/Refactoring/RefactoringOptions.h
@@ -14,6 +14,7 @@
 #include "clang/Tooling/Refactoring/RefactoringOption.h"
 #include "clang/Tooling/Refactoring/RefactoringOptionVisitor.h"
 #include "llvm/Support/Error.h"
+#include <optional>
 #include <type_traits>
 
 namespace clang {
diff --git a/clang/include/clang/Tooling/StandaloneExecution.h b/clang/include/clang/Tooling/StandaloneExecution.h
index 8db6229..359324f 100644
--- a/clang/include/clang/Tooling/StandaloneExecution.h
+++ b/clang/include/clang/Tooling/StandaloneExecution.h
@@ -15,6 +15,7 @@
 
 #include "clang/Tooling/ArgumentsAdjusters.h"
 #include "clang/Tooling/Execution.h"
+#include <optional>
 
 namespace clang {
 namespace tooling {
diff --git a/clang/lib/ARCMigrate/Internals.h b/clang/lib/ARCMigrate/Internals.h
index 33d16fe..2c7b8bc 100644
--- a/clang/lib/ARCMigrate/Internals.h
+++ b/clang/lib/ARCMigrate/Internals.h
@@ -15,6 +15,7 @@
 #include "llvm/ADT/ArrayRef.h"
 #include "llvm/ADT/Optional.h"
 #include <list>
+#include <optional>
 
 namespace clang {
   class ASTContext;
diff --git a/clang/lib/AST/AttrImpl.cpp b/clang/lib/AST/AttrImpl.cpp
index 38d77b8..e4e25e2 100644
--- a/clang/lib/AST/AttrImpl.cpp
+++ b/clang/lib/AST/AttrImpl.cpp
@@ -14,6 +14,7 @@
 #include "clang/AST/Attr.h"
 #include "clang/AST/Expr.h"
 #include "clang/AST/Type.h"
+#include <optional>
 using namespace clang;
 
 void LoopHintAttr::printPrettyPragma(raw_ostream &OS,
diff --git a/clang/lib/AST/ComparisonCategories.cpp b/clang/lib/AST/ComparisonCategories.cpp
index f323785..2259741 100644
--- a/clang/lib/AST/ComparisonCategories.cpp
+++ b/clang/lib/AST/ComparisonCategories.cpp
@@ -17,6 +17,7 @@
 #include "clang/AST/DeclCXX.h"
 #include "clang/AST/Type.h"
 #include "llvm/ADT/SmallVector.h"
+#include <optional>
 
 using namespace clang;
 
diff --git a/clang/lib/AST/Decl.cpp b/clang/lib/AST/Decl.cpp
index 0e1bc2d..c0e1290 100644
--- a/clang/lib/AST/Decl.cpp
+++ b/clang/lib/AST/Decl.cpp
@@ -68,6 +68,7 @@
 #include <cstddef>
 #include <cstring>
 #include <memory>
+#include <optional>
 #include <string>
 #include <tuple>
 #include <type_traits>
diff --git a/clang/lib/AST/DeclTemplate.cpp b/clang/lib/AST/DeclTemplate.cpp
index 5fac054..c6f3ea2 100644
--- a/clang/lib/AST/DeclTemplate.cpp
+++ b/clang/lib/AST/DeclTemplate.cpp
@@ -35,6 +35,7 @@
 #include <cassert>
 #include <cstdint>
 #include <memory>
+#include <optional>
 #include <utility>
 
 using namespace clang;
diff --git a/clang/lib/AST/Expr.cpp b/clang/lib/AST/Expr.cpp
index a735f95..9858fbf 100644
--- a/clang/lib/AST/Expr.cpp
+++ b/clang/lib/AST/Expr.cpp
@@ -37,6 +37,7 @@
 #include "llvm/Support/raw_ostream.h"
 #include <algorithm>
 #include <cstring>
+#include <optional>
 using namespace clang;
 
 const Expr *Expr::getBestDynamicClassTypeExpr() const {
diff --git a/clang/lib/AST/ExprCXX.cpp b/clang/lib/AST/ExprCXX.cpp
index 81d4bbf..975287e 100644
--- a/clang/lib/AST/ExprCXX.cpp
+++ b/clang/lib/AST/ExprCXX.cpp
@@ -38,6 +38,7 @@
 #include <cstddef>
 #include <cstring>
 #include <memory>
+#include <optional>
 
 using namespace clang;
 
diff --git a/clang/lib/AST/ExternalASTSource.cpp b/clang/lib/AST/ExternalASTSource.cpp
index 091c0cf..ac522c8 100644
--- a/clang/lib/AST/ExternalASTSource.cpp
+++ b/clang/lib/AST/ExternalASTSource.cpp
@@ -22,6 +22,7 @@
 #include "clang/Basic/SourceManager.h"
 #include "llvm/Support/ErrorHandling.h"
 #include <cstdint>
+#include <optional>
 
 using namespace clang;
 
diff --git a/clang/lib/AST/FormatString.cpp b/clang/lib/AST/FormatString.cpp
index 4da1fb8..3e6d45b 100644
--- a/clang/lib/AST/FormatString.cpp
+++ b/clang/lib/AST/FormatString.cpp
@@ -15,6 +15,7 @@
 #include "clang/Basic/LangOptions.h"
 #include "clang/Basic/TargetInfo.h"
 #include "llvm/Support/ConvertUTF.h"
+#include <optional>
 
 using clang::analyze_format_string::ArgType;
 using clang::analyze_format_string::FormatStringHandler;
diff --git a/clang/lib/AST/ItaniumCXXABI.cpp b/clang/lib/AST/ItaniumCXXABI.cpp
index ca76861..10f33e4 100644
--- a/clang/lib/AST/ItaniumCXXABI.cpp
+++ b/clang/lib/AST/ItaniumCXXABI.cpp
@@ -26,6 +26,7 @@
 #include "clang/Basic/TargetInfo.h"
 #include "llvm/ADT/FoldingSet.h"
 #include "llvm/ADT/iterator.h"
+#include <optional>
 
 using namespace clang;
 
diff --git a/clang/lib/AST/ItaniumMangle.cpp b/clang/lib/AST/ItaniumMangle.cpp
index 0633e65..50d6775 100644
--- a/clang/lib/AST/ItaniumMangle.cpp
+++ b/clang/lib/AST/ItaniumMangle.cpp
@@ -35,6 +35,7 @@
 #include "llvm/ADT/StringExtras.h"
 #include "llvm/Support/ErrorHandling.h"
 #include "llvm/Support/raw_ostream.h"
+#include <optional>
 
 using namespace clang;
 
diff --git a/clang/lib/AST/JSONNodeDumper.cpp b/clang/lib/AST/JSONNodeDumper.cpp
index d174919..9ca1d2b 100644
--- a/clang/lib/AST/JSONNodeDumper.cpp
+++ b/clang/lib/AST/JSONNodeDumper.cpp
@@ -3,6 +3,7 @@
 #include "clang/Basic/SourceManager.h"
 #include "clang/Basic/Specifiers.h"
 #include "clang/Lex/Lexer.h"
+#include <optional>
 
 using namespace clang;
 
diff --git a/clang/lib/AST/Linkage.h b/clang/lib/AST/Linkage.h
index f4c697c7..e1c0f92 100644
--- a/clang/lib/AST/Linkage.h
+++ b/clang/lib/AST/Linkage.h
@@ -21,6 +21,7 @@
 #include "llvm/ADT/DenseMap.h"
 #include "llvm/ADT/Optional.h"
 #include "llvm/ADT/PointerIntPair.h"
+#include <optional>
 
 namespace clang {
 /// Kinds of LV computation.  The linkage side of the computation is
diff --git a/clang/lib/AST/MicrosoftMangle.cpp b/clang/lib/AST/MicrosoftMangle.cpp
index 155de89..2748fd6 100644
--- a/clang/lib/AST/MicrosoftMangle.cpp
+++ b/clang/lib/AST/MicrosoftMangle.cpp
@@ -35,6 +35,7 @@
 #include "llvm/Support/MathExtras.h"
 #include "llvm/Support/StringSaver.h"
 #include "llvm/Support/xxhash.h"
+#include <optional>
 
 using namespace clang;
 
diff --git a/clang/lib/AST/NSAPI.cpp b/clang/lib/AST/NSAPI.cpp
index db301e7..81c8f76 100644
--- a/clang/lib/AST/NSAPI.cpp
+++ b/clang/lib/AST/NSAPI.cpp
@@ -11,6 +11,7 @@
 #include "clang/AST/DeclObjC.h"
 #include "clang/AST/Expr.h"
 #include "llvm/ADT/StringSwitch.h"
+#include <optional>
 
 using namespace clang;
 
diff --git a/clang/lib/AST/OpenMPClause.cpp b/clang/lib/AST/OpenMPClause.cpp
index abbfdca..d795b70 100644
--- a/clang/lib/AST/OpenMPClause.cpp
+++ b/clang/lib/AST/OpenMPClause.cpp
@@ -23,6 +23,7 @@
 #include "llvm/Support/ErrorHandling.h"
 #include <algorithm>
 #include <cassert>
+#include <optional>
 
 using namespace clang;
 using namespace llvm;
diff --git a/clang/lib/AST/Stmt.cpp b/clang/lib/AST/Stmt.cpp
index 4081ae8..3e65543 100644
--- a/clang/lib/AST/Stmt.cpp
+++ b/clang/lib/AST/Stmt.cpp
@@ -41,6 +41,7 @@
 #include <algorithm>
 #include <cassert>
 #include <cstring>
+#include <optional>
 #include <string>
 #include <type_traits>
 #include <utility>
diff --git a/clang/lib/AST/StmtPrinter.cpp b/clang/lib/AST/StmtPrinter.cpp
index 1e0d8a5..d561685 100644
--- a/clang/lib/AST/StmtPrinter.cpp
+++ b/clang/lib/AST/StmtPrinter.cpp
@@ -54,6 +54,7 @@
 #include "llvm/Support/ErrorHandling.h"
 #include "llvm/Support/raw_ostream.h"
 #include <cassert>
+#include <optional>
 #include <string>
 
 using namespace clang;
diff --git a/clang/lib/AST/TemplateBase.cpp b/clang/lib/AST/TemplateBase.cpp
index bd3a3e9..c5a8895 100644
--- a/clang/lib/AST/TemplateBase.cpp
+++ b/clang/lib/AST/TemplateBase.cpp
@@ -40,6 +40,7 @@
 #include <cstddef>
 #include <cstdint>
 #include <cstring>
+#include <optional>
 
 using namespace clang;
 
diff --git a/clang/lib/AST/TemplateName.cpp b/clang/lib/AST/TemplateName.cpp
index f0e3e94..a16f835 100644
--- a/clang/lib/AST/TemplateName.cpp
+++ b/clang/lib/AST/TemplateName.cpp
@@ -29,6 +29,7 @@
 #include "llvm/Support/Compiler.h"
 #include "llvm/Support/raw_ostream.h"
 #include <cassert>
+#include <optional>
 #include <string>
 
 using namespace clang;
diff --git a/clang/lib/AST/Type.cpp b/clang/lib/AST/Type.cpp
index 1536fae..cac10584 100644
--- a/clang/lib/AST/Type.cpp
+++ b/clang/lib/AST/Type.cpp
@@ -50,6 +50,7 @@
 #include <cassert>
 #include <cstdint>
 #include <cstring>
+#include <optional>
 #include <type_traits>
 
 using namespace clang;
diff --git a/clang/lib/ASTMatchers/ASTMatchersInternal.cpp b/clang/lib/ASTMatchers/ASTMatchersInternal.cpp
index f9a1a59..9e755fa 100644
--- a/clang/lib/ASTMatchers/ASTMatchersInternal.cpp
+++ b/clang/lib/ASTMatchers/ASTMatchersInternal.cpp
@@ -34,6 +34,7 @@
 #include <algorithm>
 #include <cassert>
 #include <cstddef>
+#include <optional>
 #include <string>
 #include <utility>
 #include <vector>
diff --git a/clang/lib/ASTMatchers/Dynamic/Marshallers.cpp b/clang/lib/ASTMatchers/Dynamic/Marshallers.cpp
index 31cb57a..04e7d3cd 100644
--- a/clang/lib/ASTMatchers/Dynamic/Marshallers.cpp
+++ b/clang/lib/ASTMatchers/Dynamic/Marshallers.cpp
@@ -11,6 +11,7 @@
 #include "llvm/ADT/Optional.h"
 #include "llvm/ADT/StringRef.h"
 #include "llvm/Support/Regex.h"
+#include <optional>
 #include <string>
 
 static llvm::Optional<std::string>
diff --git a/clang/lib/ASTMatchers/Dynamic/Marshallers.h b/clang/lib/ASTMatchers/Dynamic/Marshallers.h
index 758205b..c6bd6d5 100644
--- a/clang/lib/ASTMatchers/Dynamic/Marshallers.h
+++ b/clang/lib/ASTMatchers/Dynamic/Marshallers.h
@@ -40,6 +40,7 @@
 #include <iterator>
 #include <limits>
 #include <memory>
+#include <optional>
 #include <string>
 #include <utility>
 #include <vector>
diff --git a/clang/lib/ASTMatchers/Dynamic/Parser.cpp b/clang/lib/ASTMatchers/Dynamic/Parser.cpp
index b9af509..ac6d643 100644
--- a/clang/lib/ASTMatchers/Dynamic/Parser.cpp
+++ b/clang/lib/ASTMatchers/Dynamic/Parser.cpp
@@ -25,6 +25,7 @@
 #include <cerrno>
 #include <cstddef>
 #include <cstdlib>
+#include <optional>
 #include <string>
 #include <utility>
 #include <vector>
diff --git a/clang/lib/ASTMatchers/Dynamic/Registry.cpp b/clang/lib/ASTMatchers/Dynamic/Registry.cpp
index 4c20a12..2fb51c7 100644
--- a/clang/lib/ASTMatchers/Dynamic/Registry.cpp
+++ b/clang/lib/ASTMatchers/Dynamic/Registry.cpp
@@ -26,6 +26,7 @@
 #include <cassert>
 #include <iterator>
 #include <memory>
+#include <optional>
 #include <set>
 #include <string>
 #include <utility>
diff --git a/clang/lib/ASTMatchers/Dynamic/VariantValue.cpp b/clang/lib/ASTMatchers/Dynamic/VariantValue.cpp
index 6cf4df4..ee60042 100644
--- a/clang/lib/ASTMatchers/Dynamic/VariantValue.cpp
+++ b/clang/lib/ASTMatchers/Dynamic/VariantValue.cpp
@@ -14,6 +14,7 @@
 #include "clang/ASTMatchers/Dynamic/VariantValue.h"
 #include "clang/Basic/LLVM.h"
 #include "llvm/ADT/STLExtras.h"
+#include <optional>
 
 namespace clang {
 namespace ast_matchers {
diff --git a/clang/lib/Analysis/BodyFarm.cpp b/clang/lib/Analysis/BodyFarm.cpp
index cf9c22f..e5fa481 100644
--- a/clang/lib/Analysis/BodyFarm.cpp
+++ b/clang/lib/Analysis/BodyFarm.cpp
@@ -24,6 +24,7 @@
 #include "clang/Basic/OperatorKinds.h"
 #include "llvm/ADT/StringSwitch.h"
 #include "llvm/Support/Debug.h"
+#include <optional>
 
 #define DEBUG_TYPE "body-farm"
 
diff --git a/clang/lib/Analysis/CFG.cpp b/clang/lib/Analysis/CFG.cpp
index 7f2c834..dd1de75 100644
--- a/clang/lib/Analysis/CFG.cpp
+++ b/clang/lib/Analysis/CFG.cpp
@@ -56,6 +56,7 @@
 #include "llvm/Support/raw_ostream.h"
 #include <cassert>
 #include <memory>
+#include <optional>
 #include <string>
 #include <tuple>
 #include <utility>
diff --git a/clang/lib/Analysis/CFGStmtMap.cpp b/clang/lib/Analysis/CFGStmtMap.cpp
index d1c23e3..82f151c 100644
--- a/clang/lib/Analysis/CFGStmtMap.cpp
+++ b/clang/lib/Analysis/CFGStmtMap.cpp
@@ -15,6 +15,7 @@
 #include "clang/AST/ParentMap.h"
 #include "clang/Analysis/CFG.h"
 #include "clang/Analysis/CFGStmtMap.h"
+#include <optional>
 
 using namespace clang;
 
diff --git a/clang/lib/Analysis/CalledOnceCheck.cpp b/clang/lib/Analysis/CalledOnceCheck.cpp
index 896562c..d68182d 100644
--- a/clang/lib/Analysis/CalledOnceCheck.cpp
+++ b/clang/lib/Analysis/CalledOnceCheck.cpp
@@ -38,6 +38,7 @@
 #include "llvm/Support/Compiler.h"
 #include "llvm/Support/ErrorHandling.h"
 #include <memory>
+#include <optional>
 
 using namespace clang;
 
diff --git a/clang/lib/Analysis/Consumed.cpp b/clang/lib/Analysis/Consumed.cpp
index 9560248..287dfbb0 100644
--- a/clang/lib/Analysis/Consumed.cpp
+++ b/clang/lib/Analysis/Consumed.cpp
@@ -34,6 +34,7 @@
 #include "llvm/Support/ErrorHandling.h"
 #include <cassert>
 #include <memory>
+#include <optional>
 #include <utility>
 
 // TODO: Adjust states of args to constructors in the same way that arguments to
diff --git a/clang/lib/Analysis/FlowSensitive/Models/UncheckedOptionalAccessModel.cpp b/clang/lib/Analysis/FlowSensitive/Models/UncheckedOptionalAccessModel.cpp
index 94e0b51..c0eb256 100644
--- a/clang/lib/Analysis/FlowSensitive/Models/UncheckedOptionalAccessModel.cpp
+++ b/clang/lib/Analysis/FlowSensitive/Models/UncheckedOptionalAccessModel.cpp
@@ -30,6 +30,7 @@
 #include "llvm/Support/ErrorHandling.h"
 #include <cassert>
 #include <memory>
+#include <optional>
 #include <utility>
 #include <vector>
 
diff --git a/clang/lib/Analysis/FlowSensitive/TypeErasedDataflowAnalysis.cpp b/clang/lib/Analysis/FlowSensitive/TypeErasedDataflowAnalysis.cpp
index 685df7b..44523a2 100644
--- a/clang/lib/Analysis/FlowSensitive/TypeErasedDataflowAnalysis.cpp
+++ b/clang/lib/Analysis/FlowSensitive/TypeErasedDataflowAnalysis.cpp
@@ -13,6 +13,7 @@
 
 #include <algorithm>
 #include <memory>
+#include <optional>
 #include <system_error>
 #include <utility>
 #include <vector>
diff --git a/clang/lib/Analysis/IssueHash.cpp b/clang/lib/Analysis/IssueHash.cpp
index 9481674..3e712fc 100644
--- a/clang/lib/Analysis/IssueHash.cpp
+++ b/clang/lib/Analysis/IssueHash.cpp
@@ -21,6 +21,7 @@
 #include "llvm/Support/Path.h"
 
 #include <functional>
+#include <optional>
 #include <sstream>
 #include <string>
 
diff --git a/clang/lib/Analysis/LiveVariables.cpp b/clang/lib/Analysis/LiveVariables.cpp
index ff7f3eb..d9194dd 100644
--- a/clang/lib/Analysis/LiveVariables.cpp
+++ b/clang/lib/Analysis/LiveVariables.cpp
@@ -19,6 +19,7 @@
 #include "llvm/ADT/DenseMap.h"
 #include "llvm/Support/raw_ostream.h"
 #include <algorithm>
+#include <optional>
 #include <vector>
 
 using namespace clang;
diff --git a/clang/lib/Analysis/MacroExpansionContext.cpp b/clang/lib/Analysis/MacroExpansionContext.cpp
index 0fb9c6a..3d98be7 100644
--- a/clang/lib/Analysis/MacroExpansionContext.cpp
+++ b/clang/lib/Analysis/MacroExpansionContext.cpp
@@ -8,6 +8,7 @@
 
 #include "clang/Analysis/MacroExpansionContext.h"
 #include "llvm/Support/Debug.h"
+#include <optional>
 
 #define DEBUG_TYPE "macro-expansion-context"
 
diff --git a/clang/lib/Analysis/PathDiagnostic.cpp b/clang/lib/Analysis/PathDiagnostic.cpp
index e2a20a0..42fa401 100644
--- a/clang/lib/Analysis/PathDiagnostic.cpp
+++ b/clang/lib/Analysis/PathDiagnostic.cpp
@@ -44,6 +44,7 @@
 #include <cassert>
 #include <cstring>
 #include <memory>
+#include <optional>
 #include <utility>
 #include <vector>
 
diff --git a/clang/lib/Analysis/ReachableCode.cpp b/clang/lib/Analysis/ReachableCode.cpp
index ce0f4f8..a375521 100644
--- a/clang/lib/Analysis/ReachableCode.cpp
+++ b/clang/lib/Analysis/ReachableCode.cpp
@@ -24,6 +24,7 @@
 #include "clang/Lex/Preprocessor.h"
 #include "llvm/ADT/BitVector.h"
 #include "llvm/ADT/SmallVector.h"
+#include <optional>
 
 using namespace clang;
 
diff --git a/clang/lib/Analysis/RetainSummaryManager.cpp b/clang/lib/Analysis/RetainSummaryManager.cpp
index f17ad91..30b37cc 100644
--- a/clang/lib/Analysis/RetainSummaryManager.cpp
+++ b/clang/lib/Analysis/RetainSummaryManager.cpp
@@ -19,6 +19,7 @@
 #include "clang/AST/DeclObjC.h"
 #include "clang/AST/ParentMap.h"
 #include "clang/ASTMatchers/ASTMatchFinder.h"
+#include <optional>
 
 using namespace clang;
 using namespace ento;
diff --git a/clang/lib/Analysis/ThreadSafety.cpp b/clang/lib/Analysis/ThreadSafety.cpp
index 7674756..feaca52 100644
--- a/clang/lib/Analysis/ThreadSafety.cpp
+++ b/clang/lib/Analysis/ThreadSafety.cpp
@@ -53,6 +53,7 @@
 #include <functional>
 #include <iterator>
 #include <memory>
+#include <optional>
 #include <string>
 #include <type_traits>
 #include <utility>
diff --git a/clang/lib/Analysis/UninitializedValues.cpp b/clang/lib/Analysis/UninitializedValues.cpp
index e2f1f6e8..ae5c3541 100644
--- a/clang/lib/Analysis/UninitializedValues.cpp
+++ b/clang/lib/Analysis/UninitializedValues.cpp
@@ -35,6 +35,7 @@
 #include "llvm/Support/Casting.h"
 #include <algorithm>
 #include <cassert>
+#include <optional>
 
 using namespace clang;
 
diff --git a/clang/lib/Analysis/UnsafeBufferUsage.cpp b/clang/lib/Analysis/UnsafeBufferUsage.cpp
index 7dd9e91..43713b4 100644
--- a/clang/lib/Analysis/UnsafeBufferUsage.cpp
+++ b/clang/lib/Analysis/UnsafeBufferUsage.cpp
@@ -10,6 +10,7 @@
 #include "clang/ASTMatchers/ASTMatchFinder.h"
 #include "clang/AST/RecursiveASTVisitor.h"
 #include "llvm/ADT/SmallVector.h"
+#include <optional>
 
 using namespace llvm;
 using namespace clang;
diff --git a/clang/lib/Basic/DiagnosticIDs.cpp b/clang/lib/Basic/DiagnosticIDs.cpp
index 66f3979..0b06a29 100644
--- a/clang/lib/Basic/DiagnosticIDs.cpp
+++ b/clang/lib/Basic/DiagnosticIDs.cpp
@@ -18,6 +18,7 @@
 #include "llvm/ADT/SmallVector.h"
 #include "llvm/Support/ErrorHandling.h"
 #include <map>
+#include <optional>
 using namespace clang;
 
 //===----------------------------------------------------------------------===//
diff --git a/clang/lib/Basic/ProfileList.cpp b/clang/lib/Basic/ProfileList.cpp
index 0f049b1..136924f 100644
--- a/clang/lib/Basic/ProfileList.cpp
+++ b/clang/lib/Basic/ProfileList.cpp
@@ -17,6 +17,7 @@
 #include "llvm/Support/SpecialCaseList.h"
 
 #include "llvm/Support/raw_ostream.h"
+#include <optional>
 
 using namespace clang;
 
diff --git a/clang/lib/Basic/Sarif.cpp b/clang/lib/Basic/Sarif.cpp
index 2c1eebc..52f22f2 100644
--- a/clang/lib/Basic/Sarif.cpp
+++ b/clang/lib/Basic/Sarif.cpp
@@ -25,6 +25,7 @@
 #include "llvm/Support/JSON.h"
 #include "llvm/Support/Path.h"
 
+#include <optional>
 #include <string>
 #include <utility>
 
diff --git a/clang/lib/Basic/SourceManager.cpp b/clang/lib/Basic/SourceManager.cpp
index 63dd4d6..6fbeb38 100644
--- a/clang/lib/Basic/SourceManager.cpp
+++ b/clang/lib/Basic/SourceManager.cpp
@@ -38,6 +38,7 @@
 #include <cstddef>
 #include <cstdint>
 #include <memory>
+#include <optional>
 #include <tuple>
 #include <utility>
 #include <vector>
diff --git a/clang/lib/Basic/Targets/AArch64.cpp b/clang/lib/Basic/Targets/AArch64.cpp
index d7893c1..4097796 100644
--- a/clang/lib/Basic/Targets/AArch64.cpp
+++ b/clang/lib/Basic/Targets/AArch64.cpp
@@ -19,6 +19,7 @@
 #include "llvm/ADT/StringSwitch.h"
 #include "llvm/Support/AArch64TargetParser.h"
 #include "llvm/Support/ARMTargetParserCommon.h"
+#include <optional>
 
 using namespace clang;
 using namespace clang::targets;
diff --git a/clang/lib/Basic/Targets/AArch64.h b/clang/lib/Basic/Targets/AArch64.h
index 95edf69..33d5d11 100644
--- a/clang/lib/Basic/Targets/AArch64.h
+++ b/clang/lib/Basic/Targets/AArch64.h
@@ -16,6 +16,7 @@
 #include "OSTargets.h"
 #include "clang/Basic/TargetBuiltins.h"
 #include "llvm/Support/AArch64TargetParser.h"
+#include <optional>
 
 namespace clang {
 namespace targets {
diff --git a/clang/lib/Basic/Targets/M68k.cpp b/clang/lib/Basic/Targets/M68k.cpp
index 868437c..be3ab89 100644
--- a/clang/lib/Basic/Targets/M68k.cpp
+++ b/clang/lib/Basic/Targets/M68k.cpp
@@ -21,6 +21,7 @@
 #include <cstdint>
 #include <cstring>
 #include <limits>
+#include <optional>
 
 namespace clang {
 namespace targets {
diff --git a/clang/lib/Basic/Targets/M68k.h b/clang/lib/Basic/Targets/M68k.h
index a42ca67..b68baeb 100644
--- a/clang/lib/Basic/Targets/M68k.h
+++ b/clang/lib/Basic/Targets/M68k.h
@@ -18,6 +18,7 @@
 #include "clang/Basic/TargetOptions.h"
 #include "llvm/ADT/Triple.h"
 #include "llvm/Support/Compiler.h"
+#include <optional>
 
 namespace clang {
 namespace targets {
diff --git a/clang/lib/Basic/Targets/RISCV.h b/clang/lib/Basic/Targets/RISCV.h
index 47096bd..30988ae 100644
--- a/clang/lib/Basic/Targets/RISCV.h
+++ b/clang/lib/Basic/Targets/RISCV.h
@@ -18,6 +18,7 @@
 #include "llvm/ADT/Triple.h"
 #include "llvm/Support/Compiler.h"
 #include "llvm/Support/RISCVISAInfo.h"
+#include <optional>
 
 namespace clang {
 namespace targets {
diff --git a/clang/lib/Basic/Targets/X86.cpp b/clang/lib/Basic/Targets/X86.cpp
index a6eea30..affe203 100644
--- a/clang/lib/Basic/Targets/X86.cpp
+++ b/clang/lib/Basic/Targets/X86.cpp
@@ -18,6 +18,7 @@
 #include "llvm/ADT/StringRef.h"
 #include "llvm/ADT/StringSwitch.h"
 #include "llvm/Support/X86TargetParser.h"
+#include <optional>
 
 namespace clang {
 namespace targets {
diff --git a/clang/lib/Basic/Targets/X86.h b/clang/lib/Basic/Targets/X86.h
index 3a02889..ef38c77 100644
--- a/clang/lib/Basic/Targets/X86.h
+++ b/clang/lib/Basic/Targets/X86.h
@@ -20,6 +20,7 @@
 #include "llvm/ADT/Triple.h"
 #include "llvm/Support/Compiler.h"
 #include "llvm/Support/X86TargetParser.h"
+#include <optional>
 
 namespace clang {
 namespace targets {
diff --git a/clang/lib/CodeGen/CGBuiltin.cpp b/clang/lib/CodeGen/CGBuiltin.cpp
index 479e242..3bbcb1e 100644
--- a/clang/lib/CodeGen/CGBuiltin.cpp
+++ b/clang/lib/CodeGen/CGBuiltin.cpp
@@ -56,6 +56,7 @@
 #include "llvm/Support/ConvertUTF.h"
 #include "llvm/Support/ScopedPrinter.h"
 #include "llvm/Support/X86TargetParser.h"
+#include <optional>
 #include <sstream>
 
 using namespace clang;
diff --git a/clang/lib/CodeGen/CGClass.cpp b/clang/lib/CodeGen/CGClass.cpp
index bf3b0c3..ec09c74 100644
--- a/clang/lib/CodeGen/CGClass.cpp
+++ b/clang/lib/CodeGen/CGClass.cpp
@@ -29,6 +29,7 @@
 #include "llvm/IR/Intrinsics.h"
 #include "llvm/IR/Metadata.h"
 #include "llvm/Transforms/Utils/SanitizerStats.h"
+#include <optional>
 
 using namespace clang;
 using namespace CodeGen;
diff --git a/clang/lib/CodeGen/CGDecl.cpp b/clang/lib/CodeGen/CGDecl.cpp
index 02e3790..764afed 100644
--- a/clang/lib/CodeGen/CGDecl.cpp
+++ b/clang/lib/CodeGen/CGDecl.cpp
@@ -37,6 +37,7 @@
 #include "llvm/IR/GlobalVariable.h"
 #include "llvm/IR/Intrinsics.h"
 #include "llvm/IR/Type.h"
+#include <optional>
 
 using namespace clang;
 using namespace CodeGen;
diff --git a/clang/lib/CodeGen/CGExpr.cpp b/clang/lib/CodeGen/CGExpr.cpp
index ca665db..213f6b7 100644
--- a/clang/lib/CodeGen/CGExpr.cpp
+++ b/clang/lib/CodeGen/CGExpr.cpp
@@ -42,6 +42,7 @@
 #include "llvm/Support/SaveAndRestore.h"
 #include "llvm/Transforms/Utils/SanitizerStats.h"
 
+#include <optional>
 #include <string>
 
 using namespace clang;
diff --git a/clang/lib/CodeGen/CGExprConstant.cpp b/clang/lib/CodeGen/CGExprConstant.cpp
index 8e74f02..28c4a82 100644
--- a/clang/lib/CodeGen/CGExprConstant.cpp
+++ b/clang/lib/CodeGen/CGExprConstant.cpp
@@ -29,6 +29,7 @@
 #include "llvm/IR/DataLayout.h"
 #include "llvm/IR/Function.h"
 #include "llvm/IR/GlobalVariable.h"
+#include <optional>
 using namespace clang;
 using namespace CodeGen;
 
diff --git a/clang/lib/CodeGen/CGExprScalar.cpp b/clang/lib/CodeGen/CGExprScalar.cpp
index b4c1966..992edc0 100644
--- a/clang/lib/CodeGen/CGExprScalar.cpp
+++ b/clang/lib/CodeGen/CGExprScalar.cpp
@@ -43,6 +43,7 @@
 #include "llvm/IR/Module.h"
 #include "llvm/Support/TypeSize.h"
 #include <cstdarg>
+#include <optional>
 
 using namespace clang;
 using namespace CodeGen;
diff --git a/clang/lib/CodeGen/CGHLSLRuntime.h b/clang/lib/CodeGen/CGHLSLRuntime.h
index 5cc2c89..29a849c 100644
--- a/clang/lib/CodeGen/CGHLSLRuntime.h
+++ b/clang/lib/CodeGen/CGHLSLRuntime.h
@@ -24,6 +24,7 @@
 #include "llvm/ADT/StringRef.h"
 #include "llvm/Frontend/HLSL/HLSLResource.h"
 
+#include <optional>
 #include <vector>
 
 namespace llvm {
diff --git a/clang/lib/CodeGen/CGLoopInfo.cpp b/clang/lib/CodeGen/CGLoopInfo.cpp
index d2b0f16..d6036fd 100644
--- a/clang/lib/CodeGen/CGLoopInfo.cpp
+++ b/clang/lib/CodeGen/CGLoopInfo.cpp
@@ -17,6 +17,7 @@
 #include "llvm/IR/InstrTypes.h"
 #include "llvm/IR/Instructions.h"
 #include "llvm/IR/Metadata.h"
+#include <optional>
 using namespace clang::CodeGen;
 using namespace llvm;
 
diff --git a/clang/lib/CodeGen/CGObjC.cpp b/clang/lib/CodeGen/CGObjC.cpp
index 42c766a..200396b 100644
--- a/clang/lib/CodeGen/CGObjC.cpp
+++ b/clang/lib/CodeGen/CGObjC.cpp
@@ -29,6 +29,7 @@
 #include "llvm/IR/Constants.h"
 #include "llvm/IR/DataLayout.h"
 #include "llvm/IR/InlineAsm.h"
+#include <optional>
 using namespace clang;
 using namespace CodeGen;
 
diff --git a/clang/lib/CodeGen/CGOpenMPRuntime.cpp b/clang/lib/CodeGen/CGOpenMPRuntime.cpp
index 2b99b30..d766263 100644
--- a/clang/lib/CodeGen/CGOpenMPRuntime.cpp
+++ b/clang/lib/CodeGen/CGOpenMPRuntime.cpp
@@ -42,6 +42,7 @@
 #include "llvm/Support/raw_ostream.h"
 #include <cassert>
 #include <numeric>
+#include <optional>
 
 using namespace clang;
 using namespace CodeGen;
diff --git a/clang/lib/CodeGen/CGStmt.cpp b/clang/lib/CodeGen/CGStmt.cpp
index 2820349..ce7ab9e 100644
--- a/clang/lib/CodeGen/CGStmt.cpp
+++ b/clang/lib/CodeGen/CGStmt.cpp
@@ -32,6 +32,7 @@
 #include "llvm/IR/Intrinsics.h"
 #include "llvm/IR/MDBuilder.h"
 #include "llvm/Support/SaveAndRestore.h"
+#include <optional>
 
 using namespace clang;
 using namespace CodeGen;
diff --git a/clang/lib/CodeGen/CGStmtOpenMP.cpp b/clang/lib/CodeGen/CGStmtOpenMP.cpp
index 65fd2a6..27f44f1 100644
--- a/clang/lib/CodeGen/CGStmtOpenMP.cpp
+++ b/clang/lib/CodeGen/CGStmtOpenMP.cpp
@@ -34,6 +34,7 @@
 #include "llvm/IR/IntrinsicInst.h"
 #include "llvm/IR/Metadata.h"
 #include "llvm/Support/AtomicOrdering.h"
+#include <optional>
 using namespace clang;
 using namespace CodeGen;
 using namespace llvm::omp;
diff --git a/clang/lib/CodeGen/CodeGenAction.cpp b/clang/lib/CodeGen/CodeGenAction.cpp
index 4b8e1d8..083d6b6 100644
--- a/clang/lib/CodeGen/CodeGenAction.cpp
+++ b/clang/lib/CodeGen/CodeGenAction.cpp
@@ -49,6 +49,7 @@
 #include "llvm/Transforms/IPO/Internalize.h"
 
 #include <memory>
+#include <optional>
 using namespace clang;
 using namespace llvm;
 
diff --git a/clang/lib/CodeGen/CodeGenFunction.cpp b/clang/lib/CodeGen/CodeGenFunction.cpp
index f8617f9..6dafd4a 100644
--- a/clang/lib/CodeGen/CodeGenFunction.cpp
+++ b/clang/lib/CodeGen/CodeGenFunction.cpp
@@ -46,6 +46,7 @@
 #include "llvm/Support/CRC.h"
 #include "llvm/Transforms/Scalar/LowerExpectIntrinsic.h"
 #include "llvm/Transforms/Utils/PromoteMemToReg.h"
+#include <optional>
 
 using namespace clang;
 using namespace CodeGen;
diff --git a/clang/lib/CodeGen/CodeGenFunction.h b/clang/lib/CodeGen/CodeGenFunction.h
index 5282874..10b9271 100644
--- a/clang/lib/CodeGen/CodeGenFunction.h
+++ b/clang/lib/CodeGen/CodeGenFunction.h
@@ -41,6 +41,7 @@
 #include "llvm/IR/ValueHandle.h"
 #include "llvm/Support/Debug.h"
 #include "llvm/Transforms/Utils/SanitizerStats.h"
+#include <optional>
 
 namespace llvm {
 class BasicBlock;
diff --git a/clang/lib/CodeGen/CodeGenModule.cpp b/clang/lib/CodeGen/CodeGenModule.cpp
index 6e37676..446874f 100644
--- a/clang/lib/CodeGen/CodeGenModule.cpp
+++ b/clang/lib/CodeGen/CodeGenModule.cpp
@@ -69,6 +69,7 @@
 #include "llvm/Support/TimeProfiler.h"
 #include "llvm/Support/X86TargetParser.h"
 #include "llvm/Support/xxhash.h"
+#include <optional>
 
 using namespace clang;
 using namespace CodeGen;
diff --git a/clang/lib/CodeGen/CodeGenModule.h b/clang/lib/CodeGen/CodeGenModule.h
index d23f5a9..689d554 100644
--- a/clang/lib/CodeGen/CodeGenModule.h
+++ b/clang/lib/CodeGen/CodeGenModule.h
@@ -36,6 +36,7 @@
 #include "llvm/IR/Module.h"
 #include "llvm/IR/ValueHandle.h"
 #include "llvm/Transforms/Utils/SanitizerStats.h"
+#include <optional>
 
 namespace llvm {
 class Module;
diff --git a/clang/lib/CodeGen/CodeGenPGO.cpp b/clang/lib/CodeGen/CodeGenPGO.cpp
index 6ee052d..c581af2 100644
--- a/clang/lib/CodeGen/CodeGenPGO.cpp
+++ b/clang/lib/CodeGen/CodeGenPGO.cpp
@@ -21,6 +21,7 @@
 #include "llvm/Support/Endian.h"
 #include "llvm/Support/FileSystem.h"
 #include "llvm/Support/MD5.h"
+#include <optional>
 
 static llvm::cl::opt<bool>
     EnableValueProfiling("enable-value-profiling",
diff --git a/clang/lib/CodeGen/CodeGenPGO.h b/clang/lib/CodeGen/CodeGenPGO.h
index 7ebd42a..048251f 100644
--- a/clang/lib/CodeGen/CodeGenPGO.h
+++ b/clang/lib/CodeGen/CodeGenPGO.h
@@ -19,6 +19,7 @@
 #include "llvm/ProfileData/InstrProfReader.h"
 #include <array>
 #include <memory>
+#include <optional>
 
 namespace clang {
 namespace CodeGen {
diff --git a/clang/lib/CodeGen/CoverageMappingGen.cpp b/clang/lib/CodeGen/CoverageMappingGen.cpp
index 14db4f0..3fd7f10 100644
--- a/clang/lib/CodeGen/CoverageMappingGen.cpp
+++ b/clang/lib/CodeGen/CoverageMappingGen.cpp
@@ -26,6 +26,7 @@
 #include "llvm/ProfileData/InstrProfReader.h"
 #include "llvm/Support/FileSystem.h"
 #include "llvm/Support/Path.h"
+#include <optional>
 
 // This selects the coverage mapping format defined when `InstrProfData.inc`
 // is textually included.
diff --git a/clang/lib/CodeGen/SwiftCallingConv.cpp b/clang/lib/CodeGen/SwiftCallingConv.cpp
index d4c6c96..982067c4 100644
--- a/clang/lib/CodeGen/SwiftCallingConv.cpp
+++ b/clang/lib/CodeGen/SwiftCallingConv.cpp
@@ -15,6 +15,7 @@
 #include "CodeGenModule.h"
 #include "TargetInfo.h"
 #include "clang/Basic/TargetInfo.h"
+#include <optional>
 
 using namespace clang;
 using namespace CodeGen;
diff --git a/clang/lib/CrossTU/CrossTranslationUnit.cpp b/clang/lib/CrossTU/CrossTranslationUnit.cpp
index c4983ea..a871eee 100644
--- a/clang/lib/CrossTU/CrossTranslationUnit.cpp
+++ b/clang/lib/CrossTU/CrossTranslationUnit.cpp
@@ -30,6 +30,7 @@
 #include "llvm/Support/raw_ostream.h"
 #include <algorithm>
 #include <fstream>
+#include <optional>
 #include <sstream>
 #include <tuple>
 
diff --git a/clang/lib/Edit/RewriteObjCFoundationAPI.cpp b/clang/lib/Edit/RewriteObjCFoundationAPI.cpp
index 1fe6a2d..89dbc96 100644
--- a/clang/lib/Edit/RewriteObjCFoundationAPI.cpp
+++ b/clang/lib/Edit/RewriteObjCFoundationAPI.cpp
@@ -18,6 +18,7 @@
 #include "clang/AST/ParentMap.h"
 #include "clang/Edit/Commit.h"
 #include "clang/Lex/Lexer.h"
+#include <optional>
 
 using namespace clang;
 using namespace edit;
diff --git a/clang/lib/ExtractAPI/Serialization/SymbolGraphSerializer.cpp b/clang/lib/ExtractAPI/Serialization/SymbolGraphSerializer.cpp
index 5c7ab65..91b86bd 100644
--- a/clang/lib/ExtractAPI/Serialization/SymbolGraphSerializer.cpp
+++ b/clang/lib/ExtractAPI/Serialization/SymbolGraphSerializer.cpp
@@ -26,6 +26,7 @@
 #include "llvm/Support/JSON.h"
 #include "llvm/Support/Path.h"
 #include "llvm/Support/VersionTuple.h"
+#include <optional>
 #include <type_traits>
 
 using namespace clang;
diff --git a/clang/lib/Format/ContinuationIndenter.h b/clang/lib/Format/ContinuationIndenter.h
index 620060e..6b4d5b6 100644
--- a/clang/lib/Format/ContinuationIndenter.h
+++ b/clang/lib/Format/ContinuationIndenter.h
@@ -20,6 +20,7 @@
 #include "clang/Format/Format.h"
 #include "llvm/Support/Regex.h"
 #include <map>
+#include <optional>
 #include <tuple>
 
 namespace clang {
diff --git a/clang/lib/Format/FormatToken.h b/clang/lib/Format/FormatToken.h
index d8c18a5..61a395e 100644
--- a/clang/lib/Format/FormatToken.h
+++ b/clang/lib/Format/FormatToken.h
@@ -20,6 +20,7 @@
 #include "clang/Format/Format.h"
 #include "clang/Lex/Lexer.h"
 #include <memory>
+#include <optional>
 #include <unordered_set>
 
 namespace clang {
diff --git a/clang/lib/Frontend/DependencyFile.cpp b/clang/lib/Frontend/DependencyFile.cpp
index e19ccdf..1c175c7 100644
--- a/clang/lib/Frontend/DependencyFile.cpp
+++ b/clang/lib/Frontend/DependencyFile.cpp
@@ -24,6 +24,7 @@
 #include "llvm/Support/FileSystem.h"
 #include "llvm/Support/Path.h"
 #include "llvm/Support/raw_ostream.h"
+#include <optional>
 
 using namespace clang;
 
diff --git a/clang/lib/Frontend/FrontendActions.cpp b/clang/lib/Frontend/FrontendActions.cpp
index f3c2afc..fa9ec46 100644
--- a/clang/lib/Frontend/FrontendActions.cpp
+++ b/clang/lib/Frontend/FrontendActions.cpp
@@ -33,6 +33,7 @@
 #include "llvm/Support/YAMLTraits.h"
 #include "llvm/Support/raw_ostream.h"
 #include <memory>
+#include <optional>
 #include <system_error>
 
 using namespace clang;
diff --git a/clang/lib/Lex/DependencyDirectivesScanner.cpp b/clang/lib/Lex/DependencyDirectivesScanner.cpp
index 183be4f..c932c0d 100644
--- a/clang/lib/Lex/DependencyDirectivesScanner.cpp
+++ b/clang/lib/Lex/DependencyDirectivesScanner.cpp
@@ -23,6 +23,7 @@
 #include "llvm/ADT/SmallString.h"
 #include "llvm/ADT/StringMap.h"
 #include "llvm/ADT/StringSwitch.h"
+#include <optional>
 
 using namespace clang;
 using namespace clang::dependency_directives_scan;
diff --git a/clang/lib/Lex/HeaderMap.cpp b/clang/lib/Lex/HeaderMap.cpp
index 2512552..2a444b5 100644
--- a/clang/lib/Lex/HeaderMap.cpp
+++ b/clang/lib/Lex/HeaderMap.cpp
@@ -23,6 +23,7 @@
 #include "llvm/Support/Debug.h"
 #include <cstring>
 #include <memory>
+#include <optional>
 using namespace clang;
 
 /// HashHMapKey - This is the 'well known' hash function required by the file
diff --git a/clang/lib/Lex/InitHeaderSearch.cpp b/clang/lib/Lex/InitHeaderSearch.cpp
index d55746b..4b527ac 100644
--- a/clang/lib/Lex/InitHeaderSearch.cpp
+++ b/clang/lib/Lex/InitHeaderSearch.cpp
@@ -26,6 +26,7 @@
 #include "llvm/Support/ErrorHandling.h"
 #include "llvm/Support/Path.h"
 #include "llvm/Support/raw_ostream.h"
+#include <optional>
 
 using namespace clang;
 using namespace clang::frontend;
diff --git a/clang/lib/Lex/Lexer.cpp b/clang/lib/Lex/Lexer.cpp
index ce48e7d..9965acb 100644
--- a/clang/lib/Lex/Lexer.cpp
+++ b/clang/lib/Lex/Lexer.cpp
@@ -43,6 +43,7 @@
 #include <cstddef>
 #include <cstdint>
 #include <cstring>
+#include <optional>
 #include <string>
 #include <tuple>
 #include <utility>
diff --git a/clang/lib/Lex/MacroInfo.cpp b/clang/lib/Lex/MacroInfo.cpp
index bfac365..819bb72 100644
--- a/clang/lib/Lex/MacroInfo.cpp
+++ b/clang/lib/Lex/MacroInfo.cpp
@@ -24,6 +24,7 @@
 #include "llvm/Support/Compiler.h"
 #include "llvm/Support/raw_ostream.h"
 #include <cassert>
+#include <optional>
 #include <utility>
 
 using namespace clang;
diff --git a/clang/lib/Lex/ModuleMap.cpp b/clang/lib/Lex/ModuleMap.cpp
index 633ea26..7292f16 100644
--- a/clang/lib/Lex/ModuleMap.cpp
+++ b/clang/lib/Lex/ModuleMap.cpp
@@ -46,6 +46,7 @@
 #include <cassert>
 #include <cstdint>
 #include <cstring>
+#include <optional>
 #include <string>
 #include <system_error>
 #include <utility>
diff --git a/clang/lib/Lex/PPDirectives.cpp b/clang/lib/Lex/PPDirectives.cpp
index 8a38fb4..3064c8c 100644
--- a/clang/lib/Lex/PPDirectives.cpp
+++ b/clang/lib/Lex/PPDirectives.cpp
@@ -47,6 +47,7 @@
 #include <cassert>
 #include <cstring>
 #include <new>
+#include <optional>
 #include <string>
 #include <utility>
 
diff --git a/clang/lib/Lex/PPLexerChange.cpp b/clang/lib/Lex/PPLexerChange.cpp
index 570728e..c997bc3 100644
--- a/clang/lib/Lex/PPLexerChange.cpp
+++ b/clang/lib/Lex/PPLexerChange.cpp
@@ -22,6 +22,7 @@
 #include "llvm/Support/FileSystem.h"
 #include "llvm/Support/MemoryBufferRef.h"
 #include "llvm/Support/Path.h"
+#include <optional>
 
 using namespace clang;
 
diff --git a/clang/lib/Lex/PPMacroExpansion.cpp b/clang/lib/Lex/PPMacroExpansion.cpp
index 9262d1c..cd60452 100644
--- a/clang/lib/Lex/PPMacroExpansion.cpp
+++ b/clang/lib/Lex/PPMacroExpansion.cpp
@@ -53,6 +53,7 @@
 #include <cstddef>
 #include <cstring>
 #include <ctime>
+#include <optional>
 #include <string>
 #include <tuple>
 #include <utility>
diff --git a/clang/lib/Lex/Pragma.cpp b/clang/lib/Lex/Pragma.cpp
index fc86f7d..ab61c72 100644
--- a/clang/lib/Lex/Pragma.cpp
+++ b/clang/lib/Lex/Pragma.cpp
@@ -48,6 +48,7 @@
 #include <cstddef>
 #include <cstdint>
 #include <limits>
+#include <optional>
 #include <string>
 #include <utility>
 #include <vector>
diff --git a/clang/lib/Lex/PreprocessingRecord.cpp b/clang/lib/Lex/PreprocessingRecord.cpp
index 1b13d09..e187fb6 100644
--- a/clang/lib/Lex/PreprocessingRecord.cpp
+++ b/clang/lib/Lex/PreprocessingRecord.cpp
@@ -31,6 +31,7 @@
 #include <cstddef>
 #include <cstring>
 #include <iterator>
+#include <optional>
 #include <utility>
 #include <vector>
 
diff --git a/clang/lib/Lex/Preprocessor.cpp b/clang/lib/Lex/Preprocessor.cpp
index 5f54c3b..87655c7 100644
--- a/clang/lib/Lex/Preprocessor.cpp
+++ b/clang/lib/Lex/Preprocessor.cpp
@@ -65,6 +65,7 @@
 #include <algorithm>
 #include <cassert>
 #include <memory>
+#include <optional>
 #include <string>
 #include <utility>
 #include <vector>
diff --git a/clang/lib/Lex/TokenLexer.cpp b/clang/lib/Lex/TokenLexer.cpp
index a64a00d..6f801db 100644
--- a/clang/lib/Lex/TokenLexer.cpp
+++ b/clang/lib/Lex/TokenLexer.cpp
@@ -31,6 +31,7 @@
 #include "llvm/ADT/iterator_range.h"
 #include <cassert>
 #include <cstring>
+#include <optional>
 
 using namespace clang;
 
diff --git a/clang/lib/Parse/ParseDecl.cpp b/clang/lib/Parse/ParseDecl.cpp
index 241a461..eec12a1 100644
--- a/clang/lib/Parse/ParseDecl.cpp
+++ b/clang/lib/Parse/ParseDecl.cpp
@@ -29,6 +29,7 @@
 #include "llvm/ADT/SmallSet.h"
 #include "llvm/ADT/SmallString.h"
 #include "llvm/ADT/StringSwitch.h"
+#include <optional>
 
 using namespace clang;
 
diff --git a/clang/lib/Parse/ParseDeclCXX.cpp b/clang/lib/Parse/ParseDeclCXX.cpp
index 6fbf804..1dadb76 100644
--- a/clang/lib/Parse/ParseDeclCXX.cpp
+++ b/clang/lib/Parse/ParseDeclCXX.cpp
@@ -27,6 +27,7 @@
 #include "clang/Sema/Scope.h"
 #include "llvm/ADT/SmallString.h"
 #include "llvm/Support/TimeProfiler.h"
+#include <optional>
 
 using namespace clang;
 
diff --git a/clang/lib/Parse/ParseExpr.cpp b/clang/lib/Parse/ParseExpr.cpp
index 34fead3..ab3b77d 100644
--- a/clang/lib/Parse/ParseExpr.cpp
+++ b/clang/lib/Parse/ParseExpr.cpp
@@ -30,6 +30,7 @@
 #include "clang/Sema/Scope.h"
 #include "clang/Sema/TypoCorrection.h"
 #include "llvm/ADT/SmallVector.h"
+#include <optional>
 using namespace clang;
 
 /// Simple precedence-based parser for binary/ternary operators.
diff --git a/clang/lib/Parse/ParseOpenMP.cpp b/clang/lib/Parse/ParseOpenMP.cpp
index 680cae7..b5e6d01 100644
--- a/clang/lib/Parse/ParseOpenMP.cpp
+++ b/clang/lib/Parse/ParseOpenMP.cpp
@@ -25,6 +25,7 @@
 #include "llvm/ADT/UniqueVector.h"
 #include "llvm/Frontend/OpenMP/OMPAssume.h"
 #include "llvm/Frontend/OpenMP/OMPContext.h"
+#include <optional>
 
 using namespace clang;
 using namespace llvm::omp;
diff --git a/clang/lib/Parse/ParsePragma.cpp b/clang/lib/Parse/ParsePragma.cpp
index d157536..445ad64 100644
--- a/clang/lib/Parse/ParsePragma.cpp
+++ b/clang/lib/Parse/ParsePragma.cpp
@@ -22,6 +22,7 @@
 #include "clang/Sema/Scope.h"
 #include "llvm/ADT/ArrayRef.h"
 #include "llvm/ADT/StringSwitch.h"
+#include <optional>
 using namespace clang;
 
 namespace {
diff --git a/clang/lib/Parse/ParseStmt.cpp b/clang/lib/Parse/ParseStmt.cpp
index e160218..9f3a4cb 100644
--- a/clang/lib/Parse/ParseStmt.cpp
+++ b/clang/lib/Parse/ParseStmt.cpp
@@ -22,6 +22,7 @@
 #include "clang/Sema/Scope.h"
 #include "clang/Sema/TypoCorrection.h"
 #include "llvm/ADT/STLExtras.h"
+#include <optional>
 
 using namespace clang;
 
diff --git a/clang/lib/Sema/AnalysisBasedWarnings.cpp b/clang/lib/Sema/AnalysisBasedWarnings.cpp
index 7f0677f..13960fd 100644
--- a/clang/lib/Sema/AnalysisBasedWarnings.cpp
+++ b/clang/lib/Sema/AnalysisBasedWarnings.cpp
@@ -48,6 +48,7 @@
 #include <algorithm>
 #include <deque>
 #include <iterator>
+#include <optional>
 
 using namespace clang;
 
diff --git a/clang/lib/Sema/Sema.cpp b/clang/lib/Sema/Sema.cpp
index e856e5a..19c75c7 100644
--- a/clang/lib/Sema/Sema.cpp
+++ b/clang/lib/Sema/Sema.cpp
@@ -49,6 +49,7 @@
 #include "llvm/ADT/STLExtras.h"
 #include "llvm/ADT/SmallPtrSet.h"
 #include "llvm/Support/TimeProfiler.h"
+#include <optional>
 
 using namespace clang;
 using namespace sema;
diff --git a/clang/lib/Sema/SemaAttr.cpp b/clang/lib/Sema/SemaAttr.cpp
index 6b4777d..572eb16 100644
--- a/clang/lib/Sema/SemaAttr.cpp
+++ b/clang/lib/Sema/SemaAttr.cpp
@@ -18,6 +18,7 @@
 #include "clang/Lex/Preprocessor.h"
 #include "clang/Sema/Lookup.h"
 #include "clang/Sema/SemaInternal.h"
+#include <optional>
 using namespace clang;
 
 //===----------------------------------------------------------------------===//
diff --git a/clang/lib/Sema/SemaAvailability.cpp b/clang/lib/Sema/SemaAvailability.cpp
index 316c013..e5aeaad 100644
--- a/clang/lib/Sema/SemaAvailability.cpp
+++ b/clang/lib/Sema/SemaAvailability.cpp
@@ -19,6 +19,7 @@
 #include "clang/Sema/DelayedDiagnostic.h"
 #include "clang/Sema/ScopeInfo.h"
 #include "clang/Sema/Sema.h"
+#include <optional>
 
 using namespace clang;
 using namespace sema;
diff --git a/clang/lib/Sema/SemaCUDA.cpp b/clang/lib/Sema/SemaCUDA.cpp
index 01349f41..58063df 100644
--- a/clang/lib/Sema/SemaCUDA.cpp
+++ b/clang/lib/Sema/SemaCUDA.cpp
@@ -24,6 +24,7 @@
 #include "clang/Sema/Template.h"
 #include "llvm/ADT/Optional.h"
 #include "llvm/ADT/SmallVector.h"
+#include <optional>
 using namespace clang;
 
 template <typename AttrT> static bool hasExplicitAttr(const VarDecl *D) {
diff --git a/clang/lib/Sema/SemaChecking.cpp b/clang/lib/Sema/SemaChecking.cpp
index 1d956fa..5bd1072 100644
--- a/clang/lib/Sema/SemaChecking.cpp
+++ b/clang/lib/Sema/SemaChecking.cpp
@@ -95,6 +95,7 @@
 #include <cstdint>
 #include <functional>
 #include <limits>
+#include <optional>
 #include <string>
 #include <tuple>
 #include <utility>
diff --git a/clang/lib/Sema/SemaCodeComplete.cpp b/clang/lib/Sema/SemaCodeComplete.cpp
index 9a0446e..0bc264c 100644
--- a/clang/lib/Sema/SemaCodeComplete.cpp
+++ b/clang/lib/Sema/SemaCodeComplete.cpp
@@ -56,6 +56,7 @@
 
 #include <list>
 #include <map>
+#include <optional>
 #include <string>
 #include <vector>
 
diff --git a/clang/lib/Sema/SemaConcept.cpp b/clang/lib/Sema/SemaConcept.cpp
index 3ab9382..6b3bb0d 100644
--- a/clang/lib/Sema/SemaConcept.cpp
+++ b/clang/lib/Sema/SemaConcept.cpp
@@ -26,6 +26,7 @@
 #include "llvm/ADT/DenseMap.h"
 #include "llvm/ADT/PointerUnion.h"
 #include "llvm/ADT/StringExtras.h"
+#include <optional>
 
 using namespace clang;
 using namespace sema;
diff --git a/clang/lib/Sema/SemaDecl.cpp b/clang/lib/Sema/SemaDecl.cpp
index 9ab53f5..44657a1 100644
--- a/clang/lib/Sema/SemaDecl.cpp
+++ b/clang/lib/Sema/SemaDecl.cpp
@@ -50,6 +50,7 @@
 #include <algorithm>
 #include <cstring>
 #include <functional>
+#include <optional>
 #include <unordered_map>
 
 using namespace clang;
diff --git a/clang/lib/Sema/SemaDeclAttr.cpp b/clang/lib/Sema/SemaDeclAttr.cpp
index 1410104..9032205 100644
--- a/clang/lib/Sema/SemaDeclAttr.cpp
+++ b/clang/lib/Sema/SemaDeclAttr.cpp
@@ -47,6 +47,7 @@
 #include "llvm/Support/Error.h"
 #include "llvm/Support/MathExtras.h"
 #include "llvm/Support/raw_ostream.h"
+#include <optional>
 
 using namespace clang;
 using namespace sema;
diff --git a/clang/lib/Sema/SemaDeclCXX.cpp b/clang/lib/Sema/SemaDeclCXX.cpp
index 96d57f4..0c8cb7b 100644
--- a/clang/lib/Sema/SemaDeclCXX.cpp
+++ b/clang/lib/Sema/SemaDeclCXX.cpp
@@ -46,6 +46,7 @@
 #include "llvm/ADT/STLExtras.h"
 #include "llvm/ADT/StringExtras.h"
 #include <map>
+#include <optional>
 #include <set>
 
 using namespace clang;
diff --git a/clang/lib/Sema/SemaExceptionSpec.cpp b/clang/lib/Sema/SemaExceptionSpec.cpp
index 1786f31..6fe0575 100644
--- a/clang/lib/Sema/SemaExceptionSpec.cpp
+++ b/clang/lib/Sema/SemaExceptionSpec.cpp
@@ -21,6 +21,7 @@
 #include "clang/Basic/SourceManager.h"
 #include "llvm/ADT/SmallPtrSet.h"
 #include "llvm/ADT/SmallString.h"
+#include <optional>
 
 namespace clang {
 
diff --git a/clang/lib/Sema/SemaExpr.cpp b/clang/lib/Sema/SemaExpr.cpp
index 93eaed1..710befe 100644
--- a/clang/lib/Sema/SemaExpr.cpp
+++ b/clang/lib/Sema/SemaExpr.cpp
@@ -56,6 +56,7 @@
 #include "llvm/Support/ConvertUTF.h"
 #include "llvm/Support/SaveAndRestore.h"
 #include "llvm/Support/TypeSize.h"
+#include <optional>
 
 using namespace clang;
 using namespace sema;
diff --git a/clang/lib/Sema/SemaExprCXX.cpp b/clang/lib/Sema/SemaExprCXX.cpp
index 080a0de..08dd6f7 100644
--- a/clang/lib/Sema/SemaExprCXX.cpp
+++ b/clang/lib/Sema/SemaExprCXX.cpp
@@ -44,6 +44,7 @@
 #include "llvm/ADT/STLExtras.h"
 #include "llvm/Support/ErrorHandling.h"
 #include "llvm/Support/TypeSize.h"
+#include <optional>
 using namespace clang;
 using namespace sema;
 
diff --git a/clang/lib/Sema/SemaExprObjC.cpp b/clang/lib/Sema/SemaExprObjC.cpp
index 9db813e..abd104b 100644
--- a/clang/lib/Sema/SemaExprObjC.cpp
+++ b/clang/lib/Sema/SemaExprObjC.cpp
@@ -27,6 +27,7 @@
 #include "clang/Sema/SemaInternal.h"
 #include "llvm/ADT/SmallString.h"
 #include "llvm/Support/ConvertUTF.h"
+#include <optional>
 
 using namespace clang;
 using namespace sema;
diff --git a/clang/lib/Sema/SemaLambda.cpp b/clang/lib/Sema/SemaLambda.cpp
index 3e8b2cf..1e4b638 100644
--- a/clang/lib/Sema/SemaLambda.cpp
+++ b/clang/lib/Sema/SemaLambda.cpp
@@ -21,6 +21,7 @@
 #include "clang/Sema/SemaInternal.h"
 #include "clang/Sema/SemaLambda.h"
 #include "llvm/ADT/STLExtras.h"
+#include <optional>
 using namespace clang;
 using namespace sema;
 
diff --git a/clang/lib/Sema/SemaLookup.cpp b/clang/lib/Sema/SemaLookup.cpp
index dedcfb5..cea8b42 100644
--- a/clang/lib/Sema/SemaLookup.cpp
+++ b/clang/lib/Sema/SemaLookup.cpp
@@ -45,6 +45,7 @@
 #include <algorithm>
 #include <iterator>
 #include <list>
+#include <optional>
 #include <set>
 #include <utility>
 #include <vector>
diff --git a/clang/lib/Sema/SemaModule.cpp b/clang/lib/Sema/SemaModule.cpp
index 0adcc68..60b4a86 100644
--- a/clang/lib/Sema/SemaModule.cpp
+++ b/clang/lib/Sema/SemaModule.cpp
@@ -15,6 +15,7 @@
 #include "clang/Lex/HeaderSearch.h"
 #include "clang/Lex/Preprocessor.h"
 #include "clang/Sema/SemaInternal.h"
+#include <optional>
 
 using namespace clang;
 using namespace sema;
diff --git a/clang/lib/Sema/SemaOpenMP.cpp b/clang/lib/Sema/SemaOpenMP.cpp
index f48707d..09c21a4 100644
--- a/clang/lib/Sema/SemaOpenMP.cpp
+++ b/clang/lib/Sema/SemaOpenMP.cpp
@@ -39,6 +39,7 @@
 #include "llvm/ADT/StringExtras.h"
 #include "llvm/Frontend/OpenMP/OMPAssume.h"
 #include "llvm/Frontend/OpenMP/OMPConstants.h"
+#include <optional>
 #include <set>
 
 using namespace clang;
diff --git a/clang/lib/Sema/SemaRISCVVectorLookup.cpp b/clang/lib/Sema/SemaRISCVVectorLookup.cpp
index 8e73064..13f9aeb 100644
--- a/clang/lib/Sema/SemaRISCVVectorLookup.cpp
+++ b/clang/lib/Sema/SemaRISCVVectorLookup.cpp
@@ -20,6 +20,7 @@
 #include "clang/Sema/Sema.h"
 #include "clang/Support/RISCVVIntrinsicUtils.h"
 #include "llvm/ADT/SmallVector.h"
+#include <optional>
 #include <string>
 #include <vector>
 
diff --git a/clang/lib/Sema/SemaStmtAsm.cpp b/clang/lib/Sema/SemaStmtAsm.cpp
index 06fc0ec..191d747 100644
--- a/clang/lib/Sema/SemaStmtAsm.cpp
+++ b/clang/lib/Sema/SemaStmtAsm.cpp
@@ -24,6 +24,7 @@
 #include "llvm/ADT/ArrayRef.h"
 #include "llvm/ADT/StringSet.h"
 #include "llvm/MC/MCParser/MCAsmParser.h"
+#include <optional>
 using namespace clang;
 using namespace sema;
 
diff --git a/clang/lib/Sema/SemaStmtAttr.cpp b/clang/lib/Sema/SemaStmtAttr.cpp
index 9ec8fe2..27a08d3 100644
--- a/clang/lib/Sema/SemaStmtAttr.cpp
+++ b/clang/lib/Sema/SemaStmtAttr.cpp
@@ -19,6 +19,7 @@
 #include "clang/Sema/ScopeInfo.h"
 #include "clang/Sema/SemaInternal.h"
 #include "llvm/ADT/StringExtras.h"
+#include <optional>
 
 using namespace clang;
 using namespace sema;
diff --git a/clang/lib/Sema/SemaTemplate.cpp b/clang/lib/Sema/SemaTemplate.cpp
index cfa28e4..27b5906 100644
--- a/clang/lib/Sema/SemaTemplate.cpp
+++ b/clang/lib/Sema/SemaTemplate.cpp
@@ -39,6 +39,7 @@
 #include "llvm/ADT/StringExtras.h"
 
 #include <iterator>
+#include <optional>
 using namespace clang;
 using namespace sema;
 
diff --git a/clang/lib/Sema/SemaTemplateDeduction.cpp b/clang/lib/Sema/SemaTemplateDeduction.cpp
index c77b0af..4a5305a 100644
--- a/clang/lib/Sema/SemaTemplateDeduction.cpp
+++ b/clang/lib/Sema/SemaTemplateDeduction.cpp
@@ -54,6 +54,7 @@
 #include "llvm/Support/ErrorHandling.h"
 #include <algorithm>
 #include <cassert>
+#include <optional>
 #include <tuple>
 #include <type_traits>
 #include <utility>
diff --git a/clang/lib/Sema/SemaTemplateInstantiate.cpp b/clang/lib/Sema/SemaTemplateInstantiate.cpp
index 097203a..e1329c4 100644
--- a/clang/lib/Sema/SemaTemplateInstantiate.cpp
+++ b/clang/lib/Sema/SemaTemplateInstantiate.cpp
@@ -36,6 +36,7 @@
 #include "clang/Sema/TemplateInstCallback.h"
 #include "llvm/Support/ErrorHandling.h"
 #include "llvm/Support/TimeProfiler.h"
+#include <optional>
 
 using namespace clang;
 using namespace sema;
diff --git a/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp b/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp
index 7d6f282..04d3a05 100644
--- a/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp
+++ b/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp
@@ -29,6 +29,7 @@
 #include "clang/Sema/Template.h"
 #include "clang/Sema/TemplateInstCallback.h"
 #include "llvm/Support/TimeProfiler.h"
+#include <optional>
 
 using namespace clang;
 
diff --git a/clang/lib/Sema/SemaTemplateVariadic.cpp b/clang/lib/Sema/SemaTemplateVariadic.cpp
index 3326b93..95a7478 100644
--- a/clang/lib/Sema/SemaTemplateVariadic.cpp
+++ b/clang/lib/Sema/SemaTemplateVariadic.cpp
@@ -18,6 +18,7 @@
 #include "clang/Sema/ScopeInfo.h"
 #include "clang/Sema/SemaInternal.h"
 #include "clang/Sema/Template.h"
+#include <optional>
 
 using namespace clang;
 
diff --git a/clang/lib/Sema/SemaType.cpp b/clang/lib/Sema/SemaType.cpp
index 04d34f3..6e8ed7c 100644
--- a/clang/lib/Sema/SemaType.cpp
+++ b/clang/lib/Sema/SemaType.cpp
@@ -41,6 +41,7 @@
 #include "llvm/IR/DerivedTypes.h"
 #include "llvm/Support/ErrorHandling.h"
 #include <bitset>
+#include <optional>
 
 using namespace clang;
 
diff --git a/clang/lib/Sema/TreeTransform.h b/clang/lib/Sema/TreeTransform.h
index b608d53..8d4f30b 100644
--- a/clang/lib/Sema/TreeTransform.h
+++ b/clang/lib/Sema/TreeTransform.h
@@ -40,6 +40,7 @@
 #include "llvm/ADT/ArrayRef.h"
 #include "llvm/Support/ErrorHandling.h"
 #include <algorithm>
+#include <optional>
 
 using namespace llvm::omp;
 
diff --git a/clang/lib/Serialization/ASTReader.cpp b/clang/lib/Serialization/ASTReader.cpp
index c47a56b..2e920e2 100644
--- a/clang/lib/Serialization/ASTReader.cpp
+++ b/clang/lib/Serialization/ASTReader.cpp
@@ -135,6 +135,7 @@
 #include <limits>
 #include <map>
 #include <memory>
+#include <optional>
 #include <string>
 #include <system_error>
 #include <tuple>
diff --git a/clang/lib/Serialization/ASTReaderStmt.cpp b/clang/lib/Serialization/ASTReaderStmt.cpp
index 6c8e0bd..b87e9ac 100644
--- a/clang/lib/Serialization/ASTReaderStmt.cpp
+++ b/clang/lib/Serialization/ASTReaderStmt.cpp
@@ -61,6 +61,7 @@
 #include <algorithm>
 #include <cassert>
 #include <cstdint>
+#include <optional>
 #include <string>
 
 using namespace clang;
diff --git a/clang/lib/Serialization/ASTWriter.cpp b/clang/lib/Serialization/ASTWriter.cpp
index af3367f..2a5618f 100644
--- a/clang/lib/Serialization/ASTWriter.cpp
+++ b/clang/lib/Serialization/ASTWriter.cpp
@@ -111,6 +111,7 @@
 #include <ctime>
 #include <limits>
 #include <memory>
+#include <optional>
 #include <queue>
 #include <tuple>
 #include <utility>
diff --git a/clang/lib/Serialization/ASTWriterDecl.cpp b/clang/lib/Serialization/ASTWriterDecl.cpp
index a63d010..2b1001a 100644
--- a/clang/lib/Serialization/ASTWriterDecl.cpp
+++ b/clang/lib/Serialization/ASTWriterDecl.cpp
@@ -23,6 +23,7 @@
 #include "clang/Serialization/ASTRecordWriter.h"
 #include "llvm/Bitstream/BitstreamWriter.h"
 #include "llvm/Support/ErrorHandling.h"
+#include <optional>
 using namespace clang;
 using namespace serialization;
 
diff --git a/clang/lib/StaticAnalyzer/Checkers/AnalyzerStatsChecker.cpp b/clang/lib/StaticAnalyzer/Checkers/AnalyzerStatsChecker.cpp
index 6154eeb..a2390d4 100644
--- a/clang/lib/StaticAnalyzer/Checkers/AnalyzerStatsChecker.cpp
+++ b/clang/lib/StaticAnalyzer/Checkers/AnalyzerStatsChecker.cpp
@@ -19,6 +19,7 @@
 #include "llvm/ADT/SmallString.h"
 #include "llvm/ADT/Statistic.h"
 #include "llvm/Support/raw_ostream.h"
+#include <optional>
 
 using namespace clang;
 using namespace ento;
diff --git a/clang/lib/StaticAnalyzer/Checkers/ArrayBoundCheckerV2.cpp b/clang/lib/StaticAnalyzer/Checkers/ArrayBoundCheckerV2.cpp
index 5be5bcd..bf3c92e 100644
--- a/clang/lib/StaticAnalyzer/Checkers/ArrayBoundCheckerV2.cpp
+++ b/clang/lib/StaticAnalyzer/Checkers/ArrayBoundCheckerV2.cpp
@@ -23,6 +23,7 @@
 #include "clang/StaticAnalyzer/Core/PathSensitive/ExprEngine.h"
 #include "llvm/ADT/SmallString.h"
 #include "llvm/Support/raw_ostream.h"
+#include <optional>
 
 using namespace clang;
 using namespace ento;
diff --git a/clang/lib/StaticAnalyzer/Checkers/BoolAssignmentChecker.cpp b/clang/lib/StaticAnalyzer/Checkers/BoolAssignmentChecker.cpp
index dad25d6..2175b34 100644
--- a/clang/lib/StaticAnalyzer/Checkers/BoolAssignmentChecker.cpp
+++ b/clang/lib/StaticAnalyzer/Checkers/BoolAssignmentChecker.cpp
@@ -17,6 +17,7 @@
 #include "clang/StaticAnalyzer/Core/Checker.h"
 #include "clang/StaticAnalyzer/Core/CheckerManager.h"
 #include "clang/StaticAnalyzer/Core/PathSensitive/CheckerContext.h"
+#include <optional>
 
 using namespace clang;
 using namespace ento;
diff --git a/clang/lib/StaticAnalyzer/Checkers/CStringChecker.cpp b/clang/lib/StaticAnalyzer/Checkers/CStringChecker.cpp
index cd760b1..e6857ce 100644
--- a/clang/lib/StaticAnalyzer/Checkers/CStringChecker.cpp
+++ b/clang/lib/StaticAnalyzer/Checkers/CStringChecker.cpp
@@ -27,6 +27,7 @@
 #include "llvm/ADT/StringExtras.h"
 #include "llvm/Support/raw_ostream.h"
 #include <functional>
+#include <optional>
 
 using namespace clang;
 using namespace ento;
diff --git a/clang/lib/StaticAnalyzer/Checkers/CastValueChecker.cpp b/clang/lib/StaticAnalyzer/Checkers/CastValueChecker.cpp
index 45f9a82..92ada1f 100644
--- a/clang/lib/StaticAnalyzer/Checkers/CastValueChecker.cpp
+++ b/clang/lib/StaticAnalyzer/Checkers/CastValueChecker.cpp
@@ -25,6 +25,7 @@
 #include "clang/StaticAnalyzer/Core/PathSensitive/CheckerContext.h"
 #include "clang/StaticAnalyzer/Core/PathSensitive/DynamicType.h"
 #include "llvm/ADT/Optional.h"
+#include <optional>
 #include <utility>
 
 using namespace clang;
diff --git a/clang/lib/StaticAnalyzer/Checkers/CheckObjCDealloc.cpp b/clang/lib/StaticAnalyzer/Checkers/CheckObjCDealloc.cpp
index a45927e..a5e26b3 100644
--- a/clang/lib/StaticAnalyzer/Checkers/CheckObjCDealloc.cpp
+++ b/clang/lib/StaticAnalyzer/Checkers/CheckObjCDealloc.cpp
@@ -45,6 +45,7 @@
 #include "clang/StaticAnalyzer/Core/PathSensitive/ProgramStateTrait.h"
 #include "clang/StaticAnalyzer/Core/PathSensitive/SymbolManager.h"
 #include "llvm/Support/raw_ostream.h"
+#include <optional>
 
 using namespace clang;
 using namespace ento;
diff --git a/clang/lib/StaticAnalyzer/Checkers/DivZeroChecker.cpp b/clang/lib/StaticAnalyzer/Checkers/DivZeroChecker.cpp
index bfd1d4c..0f04ae6 100644
--- a/clang/lib/StaticAnalyzer/Checkers/DivZeroChecker.cpp
+++ b/clang/lib/StaticAnalyzer/Checkers/DivZeroChecker.cpp
@@ -17,6 +17,7 @@
 #include "clang/StaticAnalyzer/Core/Checker.h"
 #include "clang/StaticAnalyzer/Core/CheckerManager.h"
 #include "clang/StaticAnalyzer/Core/PathSensitive/CheckerContext.h"
+#include <optional>
 
 using namespace clang;
 using namespace ento;
diff --git a/clang/lib/StaticAnalyzer/Checkers/DynamicTypePropagation.cpp b/clang/lib/StaticAnalyzer/Checkers/DynamicTypePropagation.cpp
index aaf8cca..20374ff 100644
--- a/clang/lib/StaticAnalyzer/Checkers/DynamicTypePropagation.cpp
+++ b/clang/lib/StaticAnalyzer/Checkers/DynamicTypePropagation.cpp
@@ -31,6 +31,7 @@
 #include "clang/StaticAnalyzer/Core/PathSensitive/CheckerContext.h"
 #include "clang/StaticAnalyzer/Core/PathSensitive/DynamicType.h"
 #include "clang/StaticAnalyzer/Core/PathSensitive/ProgramStateTrait.h"
+#include <optional>
 
 using namespace clang;
 using namespace ento;
diff --git a/clang/lib/StaticAnalyzer/Checkers/EnumCastOutOfRangeChecker.cpp b/clang/lib/StaticAnalyzer/Checkers/EnumCastOutOfRangeChecker.cpp
index e5088fb..1249080 100644
--- a/clang/lib/StaticAnalyzer/Checkers/EnumCastOutOfRangeChecker.cpp
+++ b/clang/lib/StaticAnalyzer/Checkers/EnumCastOutOfRangeChecker.cpp
@@ -22,6 +22,7 @@
 #include "clang/StaticAnalyzer/Checkers/BuiltinCheckerRegistration.h"
 #include "clang/StaticAnalyzer/Core/BugReporter/BugType.h"
 #include "clang/StaticAnalyzer/Core/PathSensitive/CheckerContext.h"
+#include <optional>
 
 using namespace clang;
 using namespace ento;
diff --git a/clang/lib/StaticAnalyzer/Checkers/ErrnoChecker.cpp b/clang/lib/StaticAnalyzer/Checkers/ErrnoChecker.cpp
index 2011a04..0a1b220 100644
--- a/clang/lib/StaticAnalyzer/Checkers/ErrnoChecker.cpp
+++ b/clang/lib/StaticAnalyzer/Checkers/ErrnoChecker.cpp
@@ -22,6 +22,7 @@
 #include "clang/StaticAnalyzer/Core/PathSensitive/ProgramState.h"
 #include "clang/StaticAnalyzer/Core/PathSensitive/SVals.h"
 #include "llvm/ADT/STLExtras.h"
+#include <optional>
 
 using namespace clang;
 using namespace ento;
diff --git a/clang/lib/StaticAnalyzer/Checkers/ErrnoModeling.cpp b/clang/lib/StaticAnalyzer/Checkers/ErrnoModeling.cpp
index 4f5a579..ade172c 100644
--- a/clang/lib/StaticAnalyzer/Checkers/ErrnoModeling.cpp
+++ b/clang/lib/StaticAnalyzer/Checkers/ErrnoModeling.cpp
@@ -28,6 +28,7 @@
 #include "clang/StaticAnalyzer/Core/PathSensitive/ProgramState.h"
 #include "clang/StaticAnalyzer/Core/PathSensitive/SVals.h"
 #include "llvm/ADT/STLExtras.h"
+#include <optional>
 
 using namespace clang;
 using namespace ento;
diff --git a/clang/lib/StaticAnalyzer/Checkers/ErrnoModeling.h b/clang/lib/StaticAnalyzer/Checkers/ErrnoModeling.h
index 975fe1b..765c671 100644
--- a/clang/lib/StaticAnalyzer/Checkers/ErrnoModeling.h
+++ b/clang/lib/StaticAnalyzer/Checkers/ErrnoModeling.h
@@ -16,6 +16,7 @@
 #include "clang/StaticAnalyzer/Core/PathSensitive/CheckerContext.h"
 #include "clang/StaticAnalyzer/Core/PathSensitive/ProgramState.h"
 #include "clang/StaticAnalyzer/Core/PathSensitive/SVals.h"
+#include <optional>
 
 namespace clang {
 namespace ento {
diff --git a/clang/lib/StaticAnalyzer/Checkers/ErrnoTesterChecker.cpp b/clang/lib/StaticAnalyzer/Checkers/ErrnoTesterChecker.cpp
index 3b9ff0c..9d09393 100644
--- a/clang/lib/StaticAnalyzer/Checkers/ErrnoTesterChecker.cpp
+++ b/clang/lib/StaticAnalyzer/Checkers/ErrnoTesterChecker.cpp
@@ -17,6 +17,7 @@
 #include "clang/StaticAnalyzer/Core/CheckerManager.h"
 #include "clang/StaticAnalyzer/Core/PathSensitive/CallDescription.h"
 #include "clang/StaticAnalyzer/Core/PathSensitive/CheckerContext.h"
+#include <optional>
 
 using namespace clang;
 using namespace ento;
diff --git a/clang/lib/StaticAnalyzer/Checkers/ExprInspectionChecker.cpp b/clang/lib/StaticAnalyzer/Checkers/ExprInspectionChecker.cpp
index d298bb3..3733e58 100644
--- a/clang/lib/StaticAnalyzer/Checkers/ExprInspectionChecker.cpp
+++ b/clang/lib/StaticAnalyzer/Checkers/ExprInspectionChecker.cpp
@@ -17,6 +17,7 @@
 #include "clang/StaticAnalyzer/Core/PathSensitive/DynamicExtent.h"
 #include "llvm/ADT/StringSwitch.h"
 #include "llvm/Support/ScopedPrinter.h"
+#include <optional>
 
 using namespace clang;
 using namespace ento;
diff --git a/clang/lib/StaticAnalyzer/Checkers/FuchsiaHandleChecker.cpp b/clang/lib/StaticAnalyzer/Checkers/FuchsiaHandleChecker.cpp
index eb3b89e..c093483 100644
--- a/clang/lib/StaticAnalyzer/Checkers/FuchsiaHandleChecker.cpp
+++ b/clang/lib/StaticAnalyzer/Checkers/FuchsiaHandleChecker.cpp
@@ -101,6 +101,7 @@
 #include "clang/StaticAnalyzer/Core/PathSensitive/ProgramState.h"
 #include "clang/StaticAnalyzer/Core/PathSensitive/SymExpr.h"
 #include "llvm/ADT/StringExtras.h"
+#include <optional>
 
 using namespace clang;
 using namespace ento;
diff --git a/clang/lib/StaticAnalyzer/Checkers/GTestChecker.cpp b/clang/lib/StaticAnalyzer/Checkers/GTestChecker.cpp
index dbfdff4..e9a577b 100644
--- a/clang/lib/StaticAnalyzer/Checkers/GTestChecker.cpp
+++ b/clang/lib/StaticAnalyzer/Checkers/GTestChecker.cpp
@@ -20,6 +20,7 @@
 #include "clang/StaticAnalyzer/Core/PathSensitive/CheckerContext.h"
 #include "clang/StaticAnalyzer/Core/PathSensitive/ProgramState.h"
 #include "llvm/Support/raw_ostream.h"
+#include <optional>
 
 using namespace clang;
 using namespace ento;
diff --git a/clang/lib/StaticAnalyzer/Checkers/LocalizationChecker.cpp b/clang/lib/StaticAnalyzer/Checkers/LocalizationChecker.cpp
index 9870746..6b0b6c6 100644
--- a/clang/lib/StaticAnalyzer/Checkers/LocalizationChecker.cpp
+++ b/clang/lib/StaticAnalyzer/Checkers/LocalizationChecker.cpp
@@ -29,6 +29,7 @@
 #include "clang/StaticAnalyzer/Core/PathSensitive/CheckerContext.h"
 #include "clang/StaticAnalyzer/Core/PathSensitive/ExprEngine.h"
 #include "llvm/Support/Unicode.h"
+#include <optional>
 
 using namespace clang;
 using namespace ento;
diff --git a/clang/lib/StaticAnalyzer/Checkers/MIGChecker.cpp b/clang/lib/StaticAnalyzer/Checkers/MIGChecker.cpp
index 6952953..b5f3916 100644
--- a/clang/lib/StaticAnalyzer/Checkers/MIGChecker.cpp
+++ b/clang/lib/StaticAnalyzer/Checkers/MIGChecker.cpp
@@ -30,6 +30,7 @@
 #include "clang/StaticAnalyzer/Core/PathSensitive/CallDescription.h"
 #include "clang/StaticAnalyzer/Core/PathSensitive/CallEvent.h"
 #include "clang/StaticAnalyzer/Core/PathSensitive/CheckerContext.h"
+#include <optional>
 
 using namespace clang;
 using namespace ento;
diff --git a/clang/lib/StaticAnalyzer/Checkers/MacOSKeychainAPIChecker.cpp b/clang/lib/StaticAnalyzer/Checkers/MacOSKeychainAPIChecker.cpp
index 635eb00..65867dc 100644
--- a/clang/lib/StaticAnalyzer/Checkers/MacOSKeychainAPIChecker.cpp
+++ b/clang/lib/StaticAnalyzer/Checkers/MacOSKeychainAPIChecker.cpp
@@ -21,6 +21,7 @@
 #include "clang/StaticAnalyzer/Core/PathSensitive/ProgramStateTrait.h"
 #include "llvm/ADT/SmallString.h"
 #include "llvm/Support/raw_ostream.h"
+#include <optional>
 
 using namespace clang;
 using namespace ento;
diff --git a/clang/lib/StaticAnalyzer/Checkers/MallocOverflowSecurityChecker.cpp b/clang/lib/StaticAnalyzer/Checkers/MallocOverflowSecurityChecker.cpp
index a6e8fcd..9fba90d 100644
--- a/clang/lib/StaticAnalyzer/Checkers/MallocOverflowSecurityChecker.cpp
+++ b/clang/lib/StaticAnalyzer/Checkers/MallocOverflowSecurityChecker.cpp
@@ -24,6 +24,7 @@
 #include "clang/StaticAnalyzer/Core/PathSensitive/AnalysisManager.h"
 #include "llvm/ADT/APSInt.h"
 #include "llvm/ADT/SmallVector.h"
+#include <optional>
 #include <utility>
 
 using namespace clang;
diff --git a/clang/lib/StaticAnalyzer/Checkers/NSErrorChecker.cpp b/clang/lib/StaticAnalyzer/Checkers/NSErrorChecker.cpp
index c9b17a5..6226c0e 100644
--- a/clang/lib/StaticAnalyzer/Checkers/NSErrorChecker.cpp
+++ b/clang/lib/StaticAnalyzer/Checkers/NSErrorChecker.cpp
@@ -24,6 +24,7 @@
 #include "clang/StaticAnalyzer/Core/PathSensitive/ProgramStateTrait.h"
 #include "llvm/ADT/SmallString.h"
 #include "llvm/Support/raw_ostream.h"
+#include <optional>
 
 using namespace clang;
 using namespace ento;
diff --git a/clang/lib/StaticAnalyzer/Checkers/NonnullGlobalConstantsChecker.cpp b/clang/lib/StaticAnalyzer/Checkers/NonnullGlobalConstantsChecker.cpp
index 9a15f45..e92cbae 100644
--- a/clang/lib/StaticAnalyzer/Checkers/NonnullGlobalConstantsChecker.cpp
+++ b/clang/lib/StaticAnalyzer/Checkers/NonnullGlobalConstantsChecker.cpp
@@ -26,6 +26,7 @@
 #include "clang/StaticAnalyzer/Core/CheckerManager.h"
 #include "clang/StaticAnalyzer/Core/PathSensitive/CheckerContext.h"
 #include "clang/StaticAnalyzer/Core/PathSensitive/ExprEngine.h"
+#include <optional>
 
 using namespace clang;
 using namespace ento;
diff --git a/clang/lib/StaticAnalyzer/Checkers/RetainCountChecker/RetainCountChecker.cpp b/clang/lib/StaticAnalyzer/Checkers/RetainCountChecker/RetainCountChecker.cpp
index 2e00bcd..e52a54a 100644
--- a/clang/lib/StaticAnalyzer/Checkers/RetainCountChecker/RetainCountChecker.cpp
+++ b/clang/lib/StaticAnalyzer/Checkers/RetainCountChecker/RetainCountChecker.cpp
@@ -14,6 +14,7 @@
 #include "RetainCountChecker.h"
 #include "clang/StaticAnalyzer/Core/Checker.h"
 #include "clang/StaticAnalyzer/Core/PathSensitive/CallEvent.h"
+#include <optional>
 
 using namespace clang;
 using namespace ento;
diff --git a/clang/lib/StaticAnalyzer/Checkers/ReturnValueChecker.cpp b/clang/lib/StaticAnalyzer/Checkers/ReturnValueChecker.cpp
index 9eeb450..baf443c 100644
--- a/clang/lib/StaticAnalyzer/Checkers/ReturnValueChecker.cpp
+++ b/clang/lib/StaticAnalyzer/Checkers/ReturnValueChecker.cpp
@@ -19,6 +19,7 @@
 #include "clang/StaticAnalyzer/Core/PathSensitive/CheckerContext.h"
 #include "llvm/ADT/Optional.h"
 #include "llvm/ADT/SmallVector.h"
+#include <optional>
 
 using namespace clang;
 using namespace ento;
diff --git a/clang/lib/StaticAnalyzer/Checkers/SmartPtrModeling.cpp b/clang/lib/StaticAnalyzer/Checkers/SmartPtrModeling.cpp
index 107ff5a..5b921e7 100644
--- a/clang/lib/StaticAnalyzer/Checkers/SmartPtrModeling.cpp
+++ b/clang/lib/StaticAnalyzer/Checkers/SmartPtrModeling.cpp
@@ -33,6 +33,7 @@
 #include "clang/StaticAnalyzer/Core/PathSensitive/SymbolManager.h"
 #include "llvm/ADT/StringMap.h"
 #include "llvm/Support/ErrorHandling.h"
+#include <optional>
 #include <string>
 
 using namespace clang;
diff --git a/clang/lib/StaticAnalyzer/Checkers/StreamChecker.cpp b/clang/lib/StaticAnalyzer/Checkers/StreamChecker.cpp
index 4af6a69..8ce8c4f 100644
--- a/clang/lib/StaticAnalyzer/Checkers/StreamChecker.cpp
+++ b/clang/lib/StaticAnalyzer/Checkers/StreamChecker.cpp
@@ -22,6 +22,7 @@
 #include "clang/StaticAnalyzer/Core/PathSensitive/ProgramStateTrait.h"
 #include "clang/StaticAnalyzer/Core/PathSensitive/SymbolManager.h"
 #include <functional>
+#include <optional>
 
 using namespace clang;
 using namespace ento;
diff --git a/clang/lib/StaticAnalyzer/Checkers/Taint.cpp b/clang/lib/StaticAnalyzer/Checkers/Taint.cpp
index 4416209..e20895f 100644
--- a/clang/lib/StaticAnalyzer/Checkers/Taint.cpp
+++ b/clang/lib/StaticAnalyzer/Checkers/Taint.cpp
@@ -13,6 +13,7 @@
 #include "clang/StaticAnalyzer/Checkers/Taint.h"
 #include "clang/StaticAnalyzer/Core/BugReporter/BugReporter.h"
 #include "clang/StaticAnalyzer/Core/PathSensitive/ProgramStateTrait.h"
+#include <optional>
 
 using namespace clang;
 using namespace ento;
diff --git a/clang/lib/StaticAnalyzer/Checkers/TestAfterDivZeroChecker.cpp b/clang/lib/StaticAnalyzer/Checkers/TestAfterDivZeroChecker.cpp
index eeec807..ce43c55 100644
--- a/clang/lib/StaticAnalyzer/Checkers/TestAfterDivZeroChecker.cpp
+++ b/clang/lib/StaticAnalyzer/Checkers/TestAfterDivZeroChecker.cpp
@@ -17,6 +17,7 @@
 #include "clang/StaticAnalyzer/Core/PathSensitive/CallEvent.h"
 #include "clang/StaticAnalyzer/Core/PathSensitive/CheckerContext.h"
 #include "llvm/ADT/FoldingSet.h"
+#include <optional>
 
 using namespace clang;
 using namespace ento;
diff --git a/clang/lib/StaticAnalyzer/Checkers/UndefBranchChecker.cpp b/clang/lib/StaticAnalyzer/Checkers/UndefBranchChecker.cpp
index ebe5ad5..8146d30 100644
--- a/clang/lib/StaticAnalyzer/Checkers/UndefBranchChecker.cpp
+++ b/clang/lib/StaticAnalyzer/Checkers/UndefBranchChecker.cpp
@@ -18,6 +18,7 @@
 #include "clang/StaticAnalyzer/Core/Checker.h"
 #include "clang/StaticAnalyzer/Core/CheckerManager.h"
 #include "clang/StaticAnalyzer/Core/PathSensitive/CheckerContext.h"
+#include <optional>
 #include <utility>
 
 using namespace clang;
diff --git a/clang/lib/StaticAnalyzer/Checkers/UndefCapturedBlockVarChecker.cpp b/clang/lib/StaticAnalyzer/Checkers/UndefCapturedBlockVarChecker.cpp
index 816a547..c0dd5f9 100644
--- a/clang/lib/StaticAnalyzer/Checkers/UndefCapturedBlockVarChecker.cpp
+++ b/clang/lib/StaticAnalyzer/Checkers/UndefCapturedBlockVarChecker.cpp
@@ -19,6 +19,7 @@
 #include "clang/StaticAnalyzer/Core/PathSensitive/ExprEngine.h"
 #include "llvm/ADT/SmallString.h"
 #include "llvm/Support/raw_ostream.h"
+#include <optional>
 
 using namespace clang;
 using namespace ento;
diff --git a/clang/lib/StaticAnalyzer/Checkers/UninitializedObject/UninitializedPointee.cpp b/clang/lib/StaticAnalyzer/Checkers/UninitializedObject/UninitializedPointee.cpp
index 216390a..0c3c4399b 100644
--- a/clang/lib/StaticAnalyzer/Checkers/UninitializedObject/UninitializedPointee.cpp
+++ b/clang/lib/StaticAnalyzer/Checkers/UninitializedObject/UninitializedPointee.cpp
@@ -19,6 +19,7 @@
 #include "clang/StaticAnalyzer/Core/Checker.h"
 #include "clang/StaticAnalyzer/Core/PathSensitive/CheckerContext.h"
 #include "clang/StaticAnalyzer/Core/PathSensitive/DynamicType.h"
+#include <optional>
 
 using namespace clang;
 using namespace clang::ento;
diff --git a/clang/lib/StaticAnalyzer/Checkers/UnreachableCodeChecker.cpp b/clang/lib/StaticAnalyzer/Checkers/UnreachableCodeChecker.cpp
index d231be6..032afb2 100644
--- a/clang/lib/StaticAnalyzer/Checkers/UnreachableCodeChecker.cpp
+++ b/clang/lib/StaticAnalyzer/Checkers/UnreachableCodeChecker.cpp
@@ -24,6 +24,7 @@
 #include "clang/StaticAnalyzer/Core/PathSensitive/ExplodedGraph.h"
 #include "clang/StaticAnalyzer/Core/PathSensitive/SVals.h"
 #include "llvm/ADT/SmallSet.h"
+#include <optional>
 
 using namespace clang;
 using namespace ento;
diff --git a/clang/lib/StaticAnalyzer/Checkers/VLASizeChecker.cpp b/clang/lib/StaticAnalyzer/Checkers/VLASizeChecker.cpp
index cf519b0..11b3a37 100644
--- a/clang/lib/StaticAnalyzer/Checkers/VLASizeChecker.cpp
+++ b/clang/lib/StaticAnalyzer/Checkers/VLASizeChecker.cpp
@@ -24,6 +24,7 @@
 #include "llvm/ADT/STLExtras.h"
 #include "llvm/ADT/SmallString.h"
 #include "llvm/Support/raw_ostream.h"
+#include <optional>
 
 using namespace clang;
 using namespace ento;
diff --git a/clang/lib/StaticAnalyzer/Checkers/VforkChecker.cpp b/clang/lib/StaticAnalyzer/Checkers/VforkChecker.cpp
index 04e6603..d0d16af 100644
--- a/clang/lib/StaticAnalyzer/Checkers/VforkChecker.cpp
+++ b/clang/lib/StaticAnalyzer/Checkers/VforkChecker.cpp
@@ -35,6 +35,7 @@
 #include "clang/StaticAnalyzer/Core/Checker.h"
 #include "clang/StaticAnalyzer/Core/CheckerManager.h"
 #include "clang/AST/ParentMap.h"
+#include <optional>
 
 using namespace clang;
 using namespace ento;
diff --git a/clang/lib/StaticAnalyzer/Checkers/WebKit/ASTUtils.cpp b/clang/lib/StaticAnalyzer/Checkers/WebKit/ASTUtils.cpp
index 9c7a599..d2f4bda 100644
--- a/clang/lib/StaticAnalyzer/Checkers/WebKit/ASTUtils.cpp
+++ b/clang/lib/StaticAnalyzer/Checkers/WebKit/ASTUtils.cpp
@@ -12,6 +12,7 @@
 #include "clang/AST/Decl.h"
 #include "clang/AST/DeclCXX.h"
 #include "clang/AST/ExprCXX.h"
+#include <optional>
 
 using llvm::Optional;
 namespace clang {
diff --git a/clang/lib/StaticAnalyzer/Checkers/WebKit/NoUncountedMembersChecker.cpp b/clang/lib/StaticAnalyzer/Checkers/WebKit/NoUncountedMembersChecker.cpp
index 6b4615e..edd7a1e 100644
--- a/clang/lib/StaticAnalyzer/Checkers/WebKit/NoUncountedMembersChecker.cpp
+++ b/clang/lib/StaticAnalyzer/Checkers/WebKit/NoUncountedMembersChecker.cpp
@@ -19,6 +19,7 @@
 #include "clang/StaticAnalyzer/Core/Checker.h"
 #include "llvm/ADT/DenseSet.h"
 #include "llvm/Support/Casting.h"
+#include <optional>
 
 using namespace clang;
 using namespace ento;
diff --git a/clang/lib/StaticAnalyzer/Checkers/WebKit/PtrTypesSemantics.cpp b/clang/lib/StaticAnalyzer/Checkers/WebKit/PtrTypesSemantics.cpp
index 99c3523..a7216e2 100644
--- a/clang/lib/StaticAnalyzer/Checkers/WebKit/PtrTypesSemantics.cpp
+++ b/clang/lib/StaticAnalyzer/Checkers/WebKit/PtrTypesSemantics.cpp
@@ -13,6 +13,7 @@
 #include "clang/AST/DeclCXX.h"
 #include "clang/AST/ExprCXX.h"
 #include "llvm/ADT/Optional.h"
+#include <optional>
 
 using llvm::Optional;
 using namespace clang;
diff --git a/clang/lib/StaticAnalyzer/Checkers/WebKit/RefCntblBaseVirtualDtorChecker.cpp b/clang/lib/StaticAnalyzer/Checkers/WebKit/RefCntblBaseVirtualDtorChecker.cpp
index fa9ece2..754ca76 100644
--- a/clang/lib/StaticAnalyzer/Checkers/WebKit/RefCntblBaseVirtualDtorChecker.cpp
+++ b/clang/lib/StaticAnalyzer/Checkers/WebKit/RefCntblBaseVirtualDtorChecker.cpp
@@ -14,6 +14,7 @@
 #include "clang/StaticAnalyzer/Core/BugReporter/BugReporter.h"
 #include "clang/StaticAnalyzer/Core/BugReporter/BugType.h"
 #include "clang/StaticAnalyzer/Core/Checker.h"
+#include <optional>
 
 using namespace clang;
 using namespace ento;
diff --git a/clang/lib/StaticAnalyzer/Checkers/WebKit/UncountedCallArgsChecker.cpp b/clang/lib/StaticAnalyzer/Checkers/WebKit/UncountedCallArgsChecker.cpp
index e6d0948..cc4b08d 100644
--- a/clang/lib/StaticAnalyzer/Checkers/WebKit/UncountedCallArgsChecker.cpp
+++ b/clang/lib/StaticAnalyzer/Checkers/WebKit/UncountedCallArgsChecker.cpp
@@ -19,6 +19,7 @@
 #include "clang/StaticAnalyzer/Core/BugReporter/BugType.h"
 #include "clang/StaticAnalyzer/Core/Checker.h"
 #include "llvm/ADT/DenseSet.h"
+#include <optional>
 
 using namespace clang;
 using namespace ento;
diff --git a/clang/lib/StaticAnalyzer/Checkers/WebKit/UncountedLambdaCapturesChecker.cpp b/clang/lib/StaticAnalyzer/Checkers/WebKit/UncountedLambdaCapturesChecker.cpp
index 0c952b5..dd95abb 100644
--- a/clang/lib/StaticAnalyzer/Checkers/WebKit/UncountedLambdaCapturesChecker.cpp
+++ b/clang/lib/StaticAnalyzer/Checkers/WebKit/UncountedLambdaCapturesChecker.cpp
@@ -14,6 +14,7 @@
 #include "clang/StaticAnalyzer/Core/BugReporter/BugReporter.h"
 #include "clang/StaticAnalyzer/Core/BugReporter/BugType.h"
 #include "clang/StaticAnalyzer/Core/Checker.h"
+#include <optional>
 
 using namespace clang;
 using namespace ento;
diff --git a/clang/lib/StaticAnalyzer/Checkers/WebKit/UncountedLocalVarsChecker.cpp b/clang/lib/StaticAnalyzer/Checkers/WebKit/UncountedLocalVarsChecker.cpp
index 7e86f28..74468b0 100644
--- a/clang/lib/StaticAnalyzer/Checkers/WebKit/UncountedLocalVarsChecker.cpp
+++ b/clang/lib/StaticAnalyzer/Checkers/WebKit/UncountedLocalVarsChecker.cpp
@@ -20,6 +20,7 @@
 #include "clang/StaticAnalyzer/Core/BugReporter/BugType.h"
 #include "clang/StaticAnalyzer/Core/Checker.h"
 #include "llvm/ADT/DenseSet.h"
+#include <optional>
 
 using namespace clang;
 using namespace ento;
diff --git a/clang/lib/StaticAnalyzer/Checkers/Yaml.h b/clang/lib/StaticAnalyzer/Checkers/Yaml.h
index 6c9e525..3484091 100644
--- a/clang/lib/StaticAnalyzer/Checkers/Yaml.h
+++ b/clang/lib/StaticAnalyzer/Checkers/Yaml.h
@@ -17,6 +17,7 @@
 #include "clang/StaticAnalyzer/Core/CheckerManager.h"
 #include "llvm/Support/VirtualFileSystem.h"
 #include "llvm/Support/YAMLTraits.h"
+#include <optional>
 
 namespace clang {
 namespace ento {
diff --git a/clang/lib/StaticAnalyzer/Core/AnalyzerOptions.cpp b/clang/lib/StaticAnalyzer/Core/AnalyzerOptions.cpp
index f8e32b6..fb5da11 100644
--- a/clang/lib/StaticAnalyzer/Core/AnalyzerOptions.cpp
+++ b/clang/lib/StaticAnalyzer/Core/AnalyzerOptions.cpp
@@ -23,6 +23,7 @@
 #include "llvm/Support/raw_ostream.h"
 #include <cassert>
 #include <cstddef>
+#include <optional>
 #include <utility>
 #include <vector>
 
diff --git a/clang/lib/StaticAnalyzer/Core/BugReporter.cpp b/clang/lib/StaticAnalyzer/Core/BugReporter.cpp
index 513de15..64935df 100644
--- a/clang/lib/StaticAnalyzer/Core/BugReporter.cpp
+++ b/clang/lib/StaticAnalyzer/Core/BugReporter.cpp
@@ -65,6 +65,7 @@
 #include <cstddef>
 #include <iterator>
 #include <memory>
+#include <optional>
 #include <queue>
 #include <string>
 #include <tuple>
diff --git a/clang/lib/StaticAnalyzer/Core/BugReporterVisitors.cpp b/clang/lib/StaticAnalyzer/Core/BugReporterVisitors.cpp
index 01ba95a..5281b45 100644
--- a/clang/lib/StaticAnalyzer/Core/BugReporterVisitors.cpp
+++ b/clang/lib/StaticAnalyzer/Core/BugReporterVisitors.cpp
@@ -59,6 +59,7 @@
 #include <cassert>
 #include <deque>
 #include <memory>
+#include <optional>
 #include <string>
 #include <utility>
 
diff --git a/clang/lib/StaticAnalyzer/Core/CallDescription.cpp b/clang/lib/StaticAnalyzer/Core/CallDescription.cpp
index 229fb48..38d80df 100644
--- a/clang/lib/StaticAnalyzer/Core/CallDescription.cpp
+++ b/clang/lib/StaticAnalyzer/Core/CallDescription.cpp
@@ -19,6 +19,7 @@
 #include "llvm/ADT/ArrayRef.h"
 #include "llvm/ADT/Optional.h"
 #include <iterator>
+#include <optional>
 
 using namespace llvm;
 using namespace clang;
diff --git a/clang/lib/StaticAnalyzer/Core/CallEvent.cpp b/clang/lib/StaticAnalyzer/Core/CallEvent.cpp
index 8db5781..cff2fde 100644
--- a/clang/lib/StaticAnalyzer/Core/CallEvent.cpp
+++ b/clang/lib/StaticAnalyzer/Core/CallEvent.cpp
@@ -61,6 +61,7 @@
 #include "llvm/Support/ErrorHandling.h"
 #include "llvm/Support/raw_ostream.h"
 #include <cassert>
+#include <optional>
 #include <utility>
 
 #define DEBUG_TYPE "static-analyzer-call-event"
diff --git a/clang/lib/StaticAnalyzer/Core/CheckerHelpers.cpp b/clang/lib/StaticAnalyzer/Core/CheckerHelpers.cpp
index b6f2d78..76d731b 100644
--- a/clang/lib/StaticAnalyzer/Core/CheckerHelpers.cpp
+++ b/clang/lib/StaticAnalyzer/Core/CheckerHelpers.cpp
@@ -14,6 +14,7 @@
 #include "clang/AST/Decl.h"
 #include "clang/AST/Expr.h"
 #include "clang/Lex/Preprocessor.h"
+#include <optional>
 
 namespace clang {
 
diff --git a/clang/lib/StaticAnalyzer/Core/CheckerManager.cpp b/clang/lib/StaticAnalyzer/Core/CheckerManager.cpp
index 5227766..c23e3bc 100644
--- a/clang/lib/StaticAnalyzer/Core/CheckerManager.cpp
+++ b/clang/lib/StaticAnalyzer/Core/CheckerManager.cpp
@@ -28,6 +28,7 @@
 #include "llvm/Support/ErrorHandling.h"
 #include "llvm/Support/FormatVariadic.h"
 #include <cassert>
+#include <optional>
 #include <vector>
 
 using namespace clang;
diff --git a/clang/lib/StaticAnalyzer/Core/CoreEngine.cpp b/clang/lib/StaticAnalyzer/Core/CoreEngine.cpp
index 994de60..8e15ef9 100644
--- a/clang/lib/StaticAnalyzer/Core/CoreEngine.cpp
+++ b/clang/lib/StaticAnalyzer/Core/CoreEngine.cpp
@@ -34,6 +34,7 @@
 #include <algorithm>
 #include <cassert>
 #include <memory>
+#include <optional>
 #include <utility>
 
 using namespace clang;
diff --git a/clang/lib/StaticAnalyzer/Core/ExplodedGraph.cpp b/clang/lib/StaticAnalyzer/Core/ExplodedGraph.cpp
index 294572b..23526d0 100644
--- a/clang/lib/StaticAnalyzer/Core/ExplodedGraph.cpp
+++ b/clang/lib/StaticAnalyzer/Core/ExplodedGraph.cpp
@@ -31,6 +31,7 @@
 #include "llvm/Support/Casting.h"
 #include <cassert>
 #include <memory>
+#include <optional>
 
 using namespace clang;
 using namespace ento;
diff --git a/clang/lib/StaticAnalyzer/Core/ExprEngine.cpp b/clang/lib/StaticAnalyzer/Core/ExprEngine.cpp
index de62e37..1dc1102 100644
--- a/clang/lib/StaticAnalyzer/Core/ExprEngine.cpp
+++ b/clang/lib/StaticAnalyzer/Core/ExprEngine.cpp
@@ -78,6 +78,7 @@
 #include <cassert>
 #include <cstdint>
 #include <memory>
+#include <optional>
 #include <string>
 #include <tuple>
 #include <utility>
diff --git a/clang/lib/StaticAnalyzer/Core/ExprEngineC.cpp b/clang/lib/StaticAnalyzer/Core/ExprEngineC.cpp
index 10b7022..397561f 100644
--- a/clang/lib/StaticAnalyzer/Core/ExprEngineC.cpp
+++ b/clang/lib/StaticAnalyzer/Core/ExprEngineC.cpp
@@ -14,6 +14,7 @@
 #include "clang/AST/DeclCXX.h"
 #include "clang/StaticAnalyzer/Core/CheckerManager.h"
 #include "clang/StaticAnalyzer/Core/PathSensitive/ExprEngine.h"
+#include <optional>
 
 using namespace clang;
 using namespace ento;
diff --git a/clang/lib/StaticAnalyzer/Core/ExprEngineCXX.cpp b/clang/lib/StaticAnalyzer/Core/ExprEngineCXX.cpp
index 7139180..3bee680 100644
--- a/clang/lib/StaticAnalyzer/Core/ExprEngineCXX.cpp
+++ b/clang/lib/StaticAnalyzer/Core/ExprEngineCXX.cpp
@@ -20,6 +20,7 @@
 #include "clang/StaticAnalyzer/Core/PathSensitive/CallEvent.h"
 #include "clang/StaticAnalyzer/Core/PathSensitive/ExprEngine.h"
 #include "clang/StaticAnalyzer/Core/PathSensitive/SVals.h"
+#include <optional>
 
 using namespace clang;
 using namespace ento;
diff --git a/clang/lib/StaticAnalyzer/Core/ExprEngineCallAndReturn.cpp b/clang/lib/StaticAnalyzer/Core/ExprEngineCallAndReturn.cpp
index d6968db..2db6545 100644
--- a/clang/lib/StaticAnalyzer/Core/ExprEngineCallAndReturn.cpp
+++ b/clang/lib/StaticAnalyzer/Core/ExprEngineCallAndReturn.cpp
@@ -25,6 +25,7 @@
 #include "llvm/Support/Casting.h"
 #include "llvm/Support/Compiler.h"
 #include "llvm/Support/SaveAndRestore.h"
+#include <optional>
 
 using namespace clang;
 using namespace ento;
diff --git a/clang/lib/StaticAnalyzer/Core/LoopUnrolling.cpp b/clang/lib/StaticAnalyzer/Core/LoopUnrolling.cpp
index 69599d1..357d95c 100644
--- a/clang/lib/StaticAnalyzer/Core/LoopUnrolling.cpp
+++ b/clang/lib/StaticAnalyzer/Core/LoopUnrolling.cpp
@@ -17,6 +17,7 @@
 #include "clang/StaticAnalyzer/Core/PathSensitive/CallEvent.h"
 #include "clang/StaticAnalyzer/Core/PathSensitive/CheckerContext.h"
 #include "clang/StaticAnalyzer/Core/PathSensitive/LoopUnrolling.h"
+#include <optional>
 
 using namespace clang;
 using namespace ento;
diff --git a/clang/lib/StaticAnalyzer/Core/MemRegion.cpp b/clang/lib/StaticAnalyzer/Core/MemRegion.cpp
index 0cd4ffb..1bd53ec 100644
--- a/clang/lib/StaticAnalyzer/Core/MemRegion.cpp
+++ b/clang/lib/StaticAnalyzer/Core/MemRegion.cpp
@@ -51,6 +51,7 @@
 #include <cstdint>
 #include <functional>
 #include <iterator>
+#include <optional>
 #include <string>
 #include <tuple>
 #include <utility>
diff --git a/clang/lib/StaticAnalyzer/Core/PlistDiagnostics.cpp b/clang/lib/StaticAnalyzer/Core/PlistDiagnostics.cpp
index 56f441e..7fc53b1 100644
--- a/clang/lib/StaticAnalyzer/Core/PlistDiagnostics.cpp
+++ b/clang/lib/StaticAnalyzer/Core/PlistDiagnostics.cpp
@@ -28,6 +28,7 @@
 #include "llvm/ADT/Statistic.h"
 #include "llvm/Support/Casting.h"
 #include <memory>
+#include <optional>
 
 using namespace clang;
 using namespace ento;
diff --git a/clang/lib/StaticAnalyzer/Core/ProgramState.cpp b/clang/lib/StaticAnalyzer/Core/ProgramState.cpp
index c3c9fc8..87ba432 100644
--- a/clang/lib/StaticAnalyzer/Core/ProgramState.cpp
+++ b/clang/lib/StaticAnalyzer/Core/ProgramState.cpp
@@ -19,6 +19,7 @@
 #include "clang/StaticAnalyzer/Core/PathSensitive/ExprEngine.h"
 #include "clang/StaticAnalyzer/Core/PathSensitive/ProgramStateTrait.h"
 #include "llvm/Support/raw_ostream.h"
+#include <optional>
 
 using namespace clang;
 using namespace ento;
diff --git a/clang/lib/StaticAnalyzer/Core/RangeConstraintManager.cpp b/clang/lib/StaticAnalyzer/Core/RangeConstraintManager.cpp
index 91e7155..2212170 100644
--- a/clang/lib/StaticAnalyzer/Core/RangeConstraintManager.cpp
+++ b/clang/lib/StaticAnalyzer/Core/RangeConstraintManager.cpp
@@ -26,6 +26,7 @@
 #include "llvm/Support/raw_ostream.h"
 #include <algorithm>
 #include <iterator>
+#include <optional>
 
 using namespace clang;
 using namespace ento;
diff --git a/clang/lib/StaticAnalyzer/Core/RegionStore.cpp b/clang/lib/StaticAnalyzer/Core/RegionStore.cpp
index db8a5c5..91ac36f 100644
--- a/clang/lib/StaticAnalyzer/Core/RegionStore.cpp
+++ b/clang/lib/StaticAnalyzer/Core/RegionStore.cpp
@@ -30,6 +30,7 @@
 #include "llvm/ADT/ImmutableMap.h"
 #include "llvm/ADT/Optional.h"
 #include "llvm/Support/raw_ostream.h"
+#include <optional>
 #include <utility>
 
 using namespace clang;
diff --git a/clang/lib/StaticAnalyzer/Core/SValBuilder.cpp b/clang/lib/StaticAnalyzer/Core/SValBuilder.cpp
index d30d844..0affc6f 100644
--- a/clang/lib/StaticAnalyzer/Core/SValBuilder.cpp
+++ b/clang/lib/StaticAnalyzer/Core/SValBuilder.cpp
@@ -38,6 +38,7 @@
 #include "llvm/Support/Casting.h"
 #include "llvm/Support/Compiler.h"
 #include <cassert>
+#include <optional>
 #include <tuple>
 
 using namespace clang;
diff --git a/clang/lib/StaticAnalyzer/Core/SVals.cpp b/clang/lib/StaticAnalyzer/Core/SVals.cpp
index 3172592..ae2f3ff 100644
--- a/clang/lib/StaticAnalyzer/Core/SVals.cpp
+++ b/clang/lib/StaticAnalyzer/Core/SVals.cpp
@@ -31,6 +31,7 @@
 #include "llvm/Support/ErrorHandling.h"
 #include "llvm/Support/raw_ostream.h"
 #include <cassert>
+#include <optional>
 
 using namespace clang;
 using namespace ento;
diff --git a/clang/lib/StaticAnalyzer/Core/SimpleConstraintManager.cpp b/clang/lib/StaticAnalyzer/Core/SimpleConstraintManager.cpp
index dcb6043..5c4eed9 100644
--- a/clang/lib/StaticAnalyzer/Core/SimpleConstraintManager.cpp
+++ b/clang/lib/StaticAnalyzer/Core/SimpleConstraintManager.cpp
@@ -15,6 +15,7 @@
 #include "clang/StaticAnalyzer/Core/PathSensitive/APSIntType.h"
 #include "clang/StaticAnalyzer/Core/PathSensitive/ExprEngine.h"
 #include "clang/StaticAnalyzer/Core/PathSensitive/ProgramState.h"
+#include <optional>
 
 namespace clang {
 
diff --git a/clang/lib/StaticAnalyzer/Core/SimpleSValBuilder.cpp b/clang/lib/StaticAnalyzer/Core/SimpleSValBuilder.cpp
index 77dd599..6f0abe5 100644
--- a/clang/lib/StaticAnalyzer/Core/SimpleSValBuilder.cpp
+++ b/clang/lib/StaticAnalyzer/Core/SimpleSValBuilder.cpp
@@ -15,6 +15,7 @@
 #include "clang/StaticAnalyzer/Core/PathSensitive/ExprEngine.h"
 #include "clang/StaticAnalyzer/Core/PathSensitive/ProgramState.h"
 #include "clang/StaticAnalyzer/Core/PathSensitive/SValVisitor.h"
+#include <optional>
 
 using namespace clang;
 using namespace ento;
diff --git a/clang/lib/StaticAnalyzer/Core/Store.cpp b/clang/lib/StaticAnalyzer/Core/Store.cpp
index 9e64c67..37a3a6f 100644
--- a/clang/lib/StaticAnalyzer/Core/Store.cpp
+++ b/clang/lib/StaticAnalyzer/Core/Store.cpp
@@ -35,6 +35,7 @@
 #include "llvm/Support/ErrorHandling.h"
 #include <cassert>
 #include <cstdint>
+#include <optional>
 
 using namespace clang;
 using namespace ento;
diff --git a/clang/lib/Tooling/ASTDiff/ASTDiff.cpp b/clang/lib/Tooling/ASTDiff/ASTDiff.cpp
index a25a7db..bfaa902 100644
--- a/clang/lib/Tooling/ASTDiff/ASTDiff.cpp
+++ b/clang/lib/Tooling/ASTDiff/ASTDiff.cpp
@@ -19,6 +19,7 @@
 
 #include <limits>
 #include <memory>
+#include <optional>
 #include <unordered_set>
 
 using namespace llvm;
diff --git a/clang/lib/Tooling/DependencyScanning/DependencyScanningFilesystem.cpp b/clang/lib/Tooling/DependencyScanning/DependencyScanningFilesystem.cpp
index 026bdfe..859497b 100644
--- a/clang/lib/Tooling/DependencyScanning/DependencyScanningFilesystem.cpp
+++ b/clang/lib/Tooling/DependencyScanning/DependencyScanningFilesystem.cpp
@@ -10,6 +10,7 @@
 #include "llvm/Support/MemoryBuffer.h"
 #include "llvm/Support/SmallVectorMemoryBuffer.h"
 #include "llvm/Support/Threading.h"
+#include <optional>
 
 using namespace clang;
 using namespace tooling;
diff --git a/clang/lib/Tooling/DependencyScanning/DependencyScanningTool.cpp b/clang/lib/Tooling/DependencyScanning/DependencyScanningTool.cpp
index 88540dd..70832f4 100644
--- a/clang/lib/Tooling/DependencyScanning/DependencyScanningTool.cpp
+++ b/clang/lib/Tooling/DependencyScanning/DependencyScanningTool.cpp
@@ -8,6 +8,7 @@
 
 #include "clang/Tooling/DependencyScanning/DependencyScanningTool.h"
 #include "clang/Frontend/Utils.h"
+#include <optional>
 
 using namespace clang;
 using namespace tooling;
diff --git a/clang/lib/Tooling/DependencyScanning/DependencyScanningWorker.cpp b/clang/lib/Tooling/DependencyScanning/DependencyScanningWorker.cpp
index 5af355a..957e016 100644
--- a/clang/lib/Tooling/DependencyScanning/DependencyScanningWorker.cpp
+++ b/clang/lib/Tooling/DependencyScanning/DependencyScanningWorker.cpp
@@ -23,6 +23,7 @@
 #include "clang/Tooling/DependencyScanning/ModuleDepCollector.h"
 #include "clang/Tooling/Tooling.h"
 #include "llvm/Support/Host.h"
+#include <optional>
 
 using namespace clang;
 using namespace tooling;
diff --git a/clang/lib/Tooling/DependencyScanning/ModuleDepCollector.cpp b/clang/lib/Tooling/DependencyScanning/ModuleDepCollector.cpp
index 61191fc..a91157c 100644
--- a/clang/lib/Tooling/DependencyScanning/ModuleDepCollector.cpp
+++ b/clang/lib/Tooling/DependencyScanning/ModuleDepCollector.cpp
@@ -14,6 +14,7 @@
 #include "clang/Tooling/DependencyScanning/DependencyScanningWorker.h"
 #include "llvm/Support/BLAKE3.h"
 #include "llvm/Support/StringSaver.h"
+#include <optional>
 
 using namespace clang;
 using namespace tooling;
diff --git a/clang/lib/Tooling/Inclusions/HeaderIncludes.cpp b/clang/lib/Tooling/Inclusions/HeaderIncludes.cpp
index 665d67e..c7128f2 100644
--- a/clang/lib/Tooling/Inclusions/HeaderIncludes.cpp
+++ b/clang/lib/Tooling/Inclusions/HeaderIncludes.cpp
@@ -13,6 +13,7 @@
 #include "llvm/ADT/Optional.h"
 #include "llvm/Support/FormatVariadic.h"
 #include "llvm/Support/Path.h"
+#include <optional>
 
 namespace clang {
 namespace tooling {
diff --git a/clang/lib/Tooling/InterpolatingCompilationDatabase.cpp b/clang/lib/Tooling/InterpolatingCompilationDatabase.cpp
index 5e424cc..338797c 100644
--- a/clang/lib/Tooling/InterpolatingCompilationDatabase.cpp
+++ b/clang/lib/Tooling/InterpolatingCompilationDatabase.cpp
@@ -58,6 +58,7 @@
 #include "llvm/Support/StringSaver.h"
 #include "llvm/Support/raw_ostream.h"
 #include <memory>
+#include <optional>
 
 namespace clang {
 namespace tooling {
diff --git a/clang/lib/Tooling/JSONCompilationDatabase.cpp b/clang/lib/Tooling/JSONCompilationDatabase.cpp
index 158b9a5..cc5bd4a0 100644
--- a/clang/lib/Tooling/JSONCompilationDatabase.cpp
+++ b/clang/lib/Tooling/JSONCompilationDatabase.cpp
@@ -34,6 +34,7 @@
 #include "llvm/Support/raw_ostream.h"
 #include <cassert>
 #include <memory>
+#include <optional>
 #include <string>
 #include <system_error>
 #include <tuple>
diff --git a/clang/lib/Tooling/Refactoring/ASTSelection.cpp b/clang/lib/Tooling/Refactoring/ASTSelection.cpp
index 9658ce5..943d4ed 100644
--- a/clang/lib/Tooling/Refactoring/ASTSelection.cpp
+++ b/clang/lib/Tooling/Refactoring/ASTSelection.cpp
@@ -10,6 +10,7 @@
 #include "clang/AST/LexicallyOrderedRecursiveASTVisitor.h"
 #include "clang/Lex/Lexer.h"
 #include "llvm/Support/SaveAndRestore.h"
+#include <optional>
 
 using namespace clang;
 using namespace tooling;
diff --git a/clang/lib/Tooling/Refactoring/ASTSelectionRequirements.cpp b/clang/lib/Tooling/Refactoring/ASTSelectionRequirements.cpp
index 70a4df0..e6a8e12 100644
--- a/clang/lib/Tooling/Refactoring/ASTSelectionRequirements.cpp
+++ b/clang/lib/Tooling/Refactoring/ASTSelectionRequirements.cpp
@@ -8,6 +8,7 @@
 
 #include "clang/Tooling/Refactoring/RefactoringActionRuleRequirements.h"
 #include "clang/AST/Attr.h"
+#include <optional>
 
 using namespace clang;
 using namespace tooling;
diff --git a/clang/lib/Tooling/Refactoring/Extract/Extract.cpp b/clang/lib/Tooling/Refactoring/Extract/Extract.cpp
index 402b561..efd29fc 100644
--- a/clang/lib/Tooling/Refactoring/Extract/Extract.cpp
+++ b/clang/lib/Tooling/Refactoring/Extract/Extract.cpp
@@ -19,6 +19,7 @@
 #include "clang/AST/ExprObjC.h"
 #include "clang/Rewrite/Core/Rewriter.h"
 #include "clang/Tooling/Refactoring/Extract/SourceExtraction.h"
+#include <optional>
 
 namespace clang {
 namespace tooling {
diff --git a/clang/lib/Tooling/Refactoring/Extract/SourceExtraction.cpp b/clang/lib/Tooling/Refactoring/Extract/SourceExtraction.cpp
index 5d57ecf..d4de57f 100644
--- a/clang/lib/Tooling/Refactoring/Extract/SourceExtraction.cpp
+++ b/clang/lib/Tooling/Refactoring/Extract/SourceExtraction.cpp
@@ -12,6 +12,7 @@
 #include "clang/AST/StmtObjC.h"
 #include "clang/Basic/SourceManager.h"
 #include "clang/Lex/Lexer.h"
+#include <optional>
 
 using namespace clang;
 
diff --git a/clang/lib/Tooling/Syntax/Tokens.cpp b/clang/lib/Tooling/Syntax/Tokens.cpp
index d0c8201..d99eda3 100644
--- a/clang/lib/Tooling/Syntax/Tokens.cpp
+++ b/clang/lib/Tooling/Syntax/Tokens.cpp
@@ -27,6 +27,7 @@
 #include <algorithm>
 #include <cassert>
 #include <iterator>
+#include <optional>
 #include <string>
 #include <utility>
 #include <vector>
diff --git a/clang/lib/Tooling/Transformer/Parsing.cpp b/clang/lib/Tooling/Transformer/Parsing.cpp
index 57df92c..dade271 100644
--- a/clang/lib/Tooling/Transformer/Parsing.cpp
+++ b/clang/lib/Tooling/Transformer/Parsing.cpp
@@ -18,6 +18,7 @@
 #include "llvm/ADT/StringRef.h"
 #include "llvm/Support/Errc.h"
 #include "llvm/Support/Error.h"
+#include <optional>
 #include <string>
 #include <utility>
 #include <vector>
diff --git a/clang/tools/clang-extdef-mapping/ClangExtDefMapGen.cpp b/clang/tools/clang-extdef-mapping/ClangExtDefMapGen.cpp
index ebeef5d..071923c 100644
--- a/clang/tools/clang-extdef-mapping/ClangExtDefMapGen.cpp
+++ b/clang/tools/clang-extdef-mapping/ClangExtDefMapGen.cpp
@@ -23,6 +23,7 @@
 #include "clang/Tooling/Tooling.h"
 #include "llvm/Support/CommandLine.h"
 #include "llvm/Support/Signals.h"
+#include <optional>
 #include <sstream>
 #include <string>
 
diff --git a/clang/tools/clang-refactor/ClangRefactor.cpp b/clang/tools/clang-refactor/ClangRefactor.cpp
index 111144b..e66bf66 100644
--- a/clang/tools/clang-refactor/ClangRefactor.cpp
+++ b/clang/tools/clang-refactor/ClangRefactor.cpp
@@ -26,6 +26,7 @@
 #include "llvm/Support/FileSystem.h"
 #include "llvm/Support/Signals.h"
 #include "llvm/Support/raw_ostream.h"
+#include <optional>
 #include <string>
 
 using namespace clang;
diff --git a/clang/tools/clang-refactor/TestSupport.cpp b/clang/tools/clang-refactor/TestSupport.cpp
index 6e7e7d5..9736d1e 100644
--- a/clang/tools/clang-refactor/TestSupport.cpp
+++ b/clang/tools/clang-refactor/TestSupport.cpp
@@ -24,6 +24,7 @@
 #include "llvm/Support/MemoryBuffer.h"
 #include "llvm/Support/Regex.h"
 #include "llvm/Support/raw_ostream.h"
+#include <optional>
 
 using namespace llvm;
 
diff --git a/clang/tools/clang-refactor/TestSupport.h b/clang/tools/clang-refactor/TestSupport.h
index c6b37b4..7ce1094 100644
--- a/clang/tools/clang-refactor/TestSupport.h
+++ b/clang/tools/clang-refactor/TestSupport.h
@@ -22,6 +22,7 @@
 #include "llvm/ADT/SmallVector.h"
 #include "llvm/Support/Error.h"
 #include <map>
+#include <optional>
 #include <string>
 
 namespace clang {
diff --git a/clang/tools/clang-repl/ClangRepl.cpp b/clang/tools/clang-repl/ClangRepl.cpp
index 8f661a5..42b2452 100644
--- a/clang/tools/clang-repl/ClangRepl.cpp
+++ b/clang/tools/clang-repl/ClangRepl.cpp
@@ -21,6 +21,7 @@
 #include "llvm/Support/ManagedStatic.h" // llvm_shutdown
 #include "llvm/Support/Signals.h"
 #include "llvm/Support/TargetSelect.h" // llvm::Initialize*
+#include <optional>
 
 static llvm::cl::list<std::string>
     ClangArgs("Xcc",
diff --git a/clang/tools/clang-scan-deps/ClangScanDeps.cpp b/clang/tools/clang-scan-deps/ClangScanDeps.cpp
index 51c7f37..f8b915d 100644
--- a/clang/tools/clang-scan-deps/ClangScanDeps.cpp
+++ b/clang/tools/clang-scan-deps/ClangScanDeps.cpp
@@ -24,6 +24,7 @@
 #include "llvm/Support/ThreadPool.h"
 #include "llvm/Support/Threading.h"
 #include <mutex>
+#include <optional>
 #include <thread>
 
 using namespace clang;
diff --git a/clang/tools/diagtool/FindDiagnosticID.cpp b/clang/tools/diagtool/FindDiagnosticID.cpp
index 328ebff..2e57a65 100644
--- a/clang/tools/diagtool/FindDiagnosticID.cpp
+++ b/clang/tools/diagtool/FindDiagnosticID.cpp
@@ -10,6 +10,7 @@
 #include "DiagnosticNames.h"
 #include "clang/Basic/AllDiagnostics.h"
 #include "llvm/Support/CommandLine.h"
+#include <optional>
 
 DEF_DIAGTOOL("find-diagnostic-id", "Print the id of the given diagnostic",
              FindDiagnosticID)
diff --git a/clang/tools/driver/cc1as_main.cpp b/clang/tools/driver/cc1as_main.cpp
index b0fca50..2a87266 100644
--- a/clang/tools/driver/cc1as_main.cpp
+++ b/clang/tools/driver/cc1as_main.cpp
@@ -54,6 +54,7 @@
 #include "llvm/Support/Timer.h"
 #include "llvm/Support/raw_ostream.h"
 #include <memory>
+#include <optional>
 #include <system_error>
 using namespace clang;
 using namespace clang::driver;
diff --git a/clang/tools/driver/cc1gen_reproducer_main.cpp b/clang/tools/driver/cc1gen_reproducer_main.cpp
index d58e8fb..08d518d 100644
--- a/clang/tools/driver/cc1gen_reproducer_main.cpp
+++ b/clang/tools/driver/cc1gen_reproducer_main.cpp
@@ -23,6 +23,7 @@
 #include "llvm/Support/VirtualFileSystem.h"
 #include "llvm/Support/YAMLTraits.h"
 #include "llvm/Support/raw_ostream.h"
+#include <optional>
 
 using namespace clang;
 
diff --git a/clang/tools/libclang/CIndex.cpp b/clang/tools/libclang/CIndex.cpp
index 07b7850..536b4ab 100644
--- a/clang/tools/libclang/CIndex.cpp
+++ b/clang/tools/libclang/CIndex.cpp
@@ -57,6 +57,7 @@
 #include "llvm/Support/raw_ostream.h"
 #include "llvm/Support/thread.h"
 #include <mutex>
+#include <optional>
 
 #if LLVM_ENABLE_THREADS != 0 && defined(__APPLE__)
 #define USE_DARWIN_THREADS
diff --git a/clang/tools/libclang/CXType.cpp b/clang/tools/libclang/CXType.cpp
index 21a7724..f5534dc 100644
--- a/clang/tools/libclang/CXType.cpp
+++ b/clang/tools/libclang/CXType.cpp
@@ -22,6 +22,7 @@
 #include "clang/AST/Type.h"
 #include "clang/Basic/AddressSpaces.h"
 #include "clang/Frontend/ASTUnit.h"
+#include <optional>
 
 using namespace clang;
 
diff --git a/clang/tools/libclang/CursorVisitor.h b/clang/tools/libclang/CursorVisitor.h
index 74190bd..b8a9d34 100644
--- a/clang/tools/libclang/CursorVisitor.h
+++ b/clang/tools/libclang/CursorVisitor.h
@@ -14,6 +14,7 @@
 #include "Index_Internal.h"
 #include "clang/AST/DeclVisitor.h"
 #include "clang/AST/TypeLocVisitor.h"
+#include <optional>
 
 namespace clang {
 class PreprocessingRecord;
diff --git a/clang/unittests/AST/ASTImporterTest.cpp b/clang/unittests/AST/ASTImporterTest.cpp
index 865574f..415cbc0 100644
--- a/clang/unittests/AST/ASTImporterTest.cpp
+++ b/clang/unittests/AST/ASTImporterTest.cpp
@@ -18,6 +18,7 @@
 #include "gtest/gtest.h"
 
 #include "ASTImporterFixtures.h"
+#include <optional>
 
 namespace clang {
 namespace ast_matchers {
diff --git a/clang/unittests/ASTMatchers/Dynamic/ParserTest.cpp b/clang/unittests/ASTMatchers/Dynamic/ParserTest.cpp
index 3124566..ac09b27 100644
--- a/clang/unittests/ASTMatchers/Dynamic/ParserTest.cpp
+++ b/clang/unittests/ASTMatchers/Dynamic/ParserTest.cpp
@@ -11,6 +11,7 @@
 #include "clang/ASTMatchers/Dynamic/Registry.h"
 #include "llvm/ADT/Optional.h"
 #include "gtest/gtest.h"
+#include <optional>
 #include <string>
 #include <vector>
 
diff --git a/clang/unittests/ASTMatchers/Dynamic/RegistryTest.cpp b/clang/unittests/ASTMatchers/Dynamic/RegistryTest.cpp
index 7c7d45a..dddd13b 100644
--- a/clang/unittests/ASTMatchers/Dynamic/RegistryTest.cpp
+++ b/clang/unittests/ASTMatchers/Dynamic/RegistryTest.cpp
@@ -9,6 +9,7 @@
 #include "../ASTMatchersTest.h"
 #include "clang/ASTMatchers/Dynamic/Registry.h"
 #include "gtest/gtest.h"
+#include <optional>
 #include <vector>
 
 namespace clang {
diff --git a/clang/unittests/Analysis/FlowSensitive/MultiVarConstantPropagationTest.cpp b/clang/unittests/Analysis/FlowSensitive/MultiVarConstantPropagationTest.cpp
index d454858..8b5fc1f 100644
--- a/clang/unittests/Analysis/FlowSensitive/MultiVarConstantPropagationTest.cpp
+++ b/clang/unittests/Analysis/FlowSensitive/MultiVarConstantPropagationTest.cpp
@@ -34,6 +34,7 @@
 #include "gtest/gtest.h"
 #include <cstdint>
 #include <memory>
+#include <optional>
 #include <ostream>
 #include <string>
 #include <utility>
diff --git a/clang/unittests/Analysis/FlowSensitive/SingleVarConstantPropagationTest.cpp b/clang/unittests/Analysis/FlowSensitive/SingleVarConstantPropagationTest.cpp
index de99f01..62ea155 100644
--- a/clang/unittests/Analysis/FlowSensitive/SingleVarConstantPropagationTest.cpp
+++ b/clang/unittests/Analysis/FlowSensitive/SingleVarConstantPropagationTest.cpp
@@ -34,6 +34,7 @@
 #include "gtest/gtest.h"
 #include <cstdint>
 #include <memory>
+#include <optional>
 #include <ostream>
 #include <string>
 #include <utility>
diff --git a/clang/unittests/Analysis/FlowSensitive/TestingSupport.h b/clang/unittests/Analysis/FlowSensitive/TestingSupport.h
index 47fa108..97cebfc 100644
--- a/clang/unittests/Analysis/FlowSensitive/TestingSupport.h
+++ b/clang/unittests/Analysis/FlowSensitive/TestingSupport.h
@@ -15,6 +15,7 @@
 
 #include <functional>
 #include <memory>
+#include <optional>
 #include <ostream>
 #include <string>
 #include <utility>
diff --git a/clang/unittests/Analysis/FlowSensitive/TransferBranchTest.cpp b/clang/unittests/Analysis/FlowSensitive/TransferBranchTest.cpp
index 9f3228d..4aadf75 100644
--- a/clang/unittests/Analysis/FlowSensitive/TransferBranchTest.cpp
+++ b/clang/unittests/Analysis/FlowSensitive/TransferBranchTest.cpp
@@ -19,6 +19,7 @@
 #include "llvm/Testing/Annotations/Annotations.h"
 #include "llvm/Testing/Support/Error.h"
 #include "gtest/gtest.h"
+#include <optional>
 
 namespace clang::dataflow::test {
 namespace {
diff --git a/clang/unittests/Analysis/FlowSensitive/TransferTest.cpp b/clang/unittests/Analysis/FlowSensitive/TransferTest.cpp
index b4bf699..95e53de 100644
--- a/clang/unittests/Analysis/FlowSensitive/TransferTest.cpp
+++ b/clang/unittests/Analysis/FlowSensitive/TransferTest.cpp
@@ -23,6 +23,7 @@
 #include "llvm/Testing/Support/Error.h"
 #include "gmock/gmock.h"
 #include "gtest/gtest.h"
+#include <optional>
 #include <string>
 #include <utility>
 
diff --git a/clang/unittests/Analysis/FlowSensitive/TypeErasedDataflowAnalysisTest.cpp b/clang/unittests/Analysis/FlowSensitive/TypeErasedDataflowAnalysisTest.cpp
index 31d5117..e03576f 100644
--- a/clang/unittests/Analysis/FlowSensitive/TypeErasedDataflowAnalysisTest.cpp
+++ b/clang/unittests/Analysis/FlowSensitive/TypeErasedDataflowAnalysisTest.cpp
@@ -34,6 +34,7 @@
 #include "gtest/gtest.h"
 #include <cassert>
 #include <memory>
+#include <optional>
 #include <ostream>
 #include <string>
 #include <utility>
diff --git a/clang/unittests/Analysis/FlowSensitive/UncheckedOptionalAccessModelTest.cpp b/clang/unittests/Analysis/FlowSensitive/UncheckedOptionalAccessModelTest.cpp
index 51bb3ae..e2abbbb 100644
--- a/clang/unittests/Analysis/FlowSensitive/UncheckedOptionalAccessModelTest.cpp
+++ b/clang/unittests/Analysis/FlowSensitive/UncheckedOptionalAccessModelTest.cpp
@@ -19,6 +19,7 @@
 #include "llvm/Support/Error.h"
 #include "gmock/gmock.h"
 #include "gtest/gtest.h"
+#include <optional>
 #include <string>
 #include <utility>
 #include <vector>
diff --git a/clang/unittests/Basic/DarwinSDKInfoTest.cpp b/clang/unittests/Basic/DarwinSDKInfoTest.cpp
index 887f74a..40c6c66 100644
--- a/clang/unittests/Basic/DarwinSDKInfoTest.cpp
+++ b/clang/unittests/Basic/DarwinSDKInfoTest.cpp
@@ -9,6 +9,7 @@
 #include "clang/Basic/DarwinSDKInfo.h"
 #include "llvm/Support/JSON.h"
 #include "gtest/gtest.h"
+#include <optional>
 
 using namespace llvm;
 using namespace clang;
diff --git a/clang/unittests/Basic/DiagnosticTest.cpp b/clang/unittests/Basic/DiagnosticTest.cpp
index 0ac9316..fd8042c 100644
--- a/clang/unittests/Basic/DiagnosticTest.cpp
+++ b/clang/unittests/Basic/DiagnosticTest.cpp
@@ -10,6 +10,7 @@
 #include "clang/Basic/DiagnosticError.h"
 #include "clang/Basic/DiagnosticIDs.h"
 #include "gtest/gtest.h"
+#include <optional>
 
 using namespace llvm;
 using namespace clang;
diff --git a/clang/unittests/Driver/SanitizerArgsTest.cpp b/clang/unittests/Driver/SanitizerArgsTest.cpp
index 8eecd53..e9252ff 100644
--- a/clang/unittests/Driver/SanitizerArgsTest.cpp
+++ b/clang/unittests/Driver/SanitizerArgsTest.cpp
@@ -27,6 +27,7 @@
 #include "gtest/gtest.h"
 #include <cstdlib>
 #include <memory>
+#include <optional>
 #include <string>
 using namespace clang;
 using namespace clang::driver;
diff --git a/clang/unittests/Frontend/ParsedSourceLocationTest.cpp b/clang/unittests/Frontend/ParsedSourceLocationTest.cpp
index 1539005..3e8f9e2 100644
--- a/clang/unittests/Frontend/ParsedSourceLocationTest.cpp
+++ b/clang/unittests/Frontend/ParsedSourceLocationTest.cpp
@@ -8,6 +8,7 @@
 
 #include "clang/Frontend/CommandLineSourceLoc.h"
 #include "gtest/gtest.h"
+#include <optional>
 
 using namespace llvm;
 using namespace clang;
diff --git a/clang/unittests/Lex/PPDependencyDirectivesTest.cpp b/clang/unittests/Lex/PPDependencyDirectivesTest.cpp
index 542fe73..840821a 100644
--- a/clang/unittests/Lex/PPDependencyDirectivesTest.cpp
+++ b/clang/unittests/Lex/PPDependencyDirectivesTest.cpp
@@ -21,6 +21,7 @@
 #include "clang/Lex/PreprocessorOptions.h"
 #include "llvm/Testing/Support/Error.h"
 #include "gtest/gtest.h"
+#include <optional>
 
 using namespace clang;
 
diff --git a/clang/unittests/Serialization/SourceLocationEncodingTest.cpp b/clang/unittests/Serialization/SourceLocationEncodingTest.cpp
index f33a909..d32e242 100644
--- a/clang/unittests/Serialization/SourceLocationEncodingTest.cpp
+++ b/clang/unittests/Serialization/SourceLocationEncodingTest.cpp
@@ -10,6 +10,7 @@
 
 #include "gtest/gtest.h"
 #include <climits>
+#include <optional>
 
 using namespace llvm;
 using namespace clang;
diff --git a/clang/unittests/StaticAnalyzer/TestReturnValueUnderConstruction.cpp b/clang/unittests/StaticAnalyzer/TestReturnValueUnderConstruction.cpp
index 6661b33..c4a3cf1 100644
--- a/clang/unittests/StaticAnalyzer/TestReturnValueUnderConstruction.cpp
+++ b/clang/unittests/StaticAnalyzer/TestReturnValueUnderConstruction.cpp
@@ -14,6 +14,7 @@
 #include "clang/StaticAnalyzer/Frontend/CheckerRegistry.h"
 #include "clang/Tooling/Tooling.h"
 #include "gtest/gtest.h"
+#include <optional>
 
 namespace clang {
 namespace ento {
diff --git a/clang/unittests/Tooling/ASTSelectionTest.cpp b/clang/unittests/Tooling/ASTSelectionTest.cpp
index 430562e..504d105 100644
--- a/clang/unittests/Tooling/ASTSelectionTest.cpp
+++ b/clang/unittests/Tooling/ASTSelectionTest.cpp
@@ -9,6 +9,7 @@
 #include "TestVisitor.h"
 #include "clang/Basic/SourceManager.h"
 #include "clang/Tooling/Refactoring/ASTSelection.h"
+#include <optional>
 
 using namespace clang;
 using namespace tooling;
diff --git a/clang/unittests/Tooling/RefactoringActionRulesTest.cpp b/clang/unittests/Tooling/RefactoringActionRulesTest.cpp
index b471cf2..e80f75a 100644
--- a/clang/unittests/Tooling/RefactoringActionRulesTest.cpp
+++ b/clang/unittests/Tooling/RefactoringActionRulesTest.cpp
@@ -16,6 +16,7 @@
 #include "clang/Tooling/Tooling.h"
 #include "llvm/Support/Errc.h"
 #include "gtest/gtest.h"
+#include <optional>
 
 using namespace clang;
 using namespace tooling;
diff --git a/clang/unittests/Tooling/RefactoringTest.cpp b/clang/unittests/Tooling/RefactoringTest.cpp
index c7a02e1..2f3bd22 100644
--- a/clang/unittests/Tooling/RefactoringTest.cpp
+++ b/clang/unittests/Tooling/RefactoringTest.cpp
@@ -29,6 +29,7 @@
 #include "llvm/ADT/SmallString.h"
 #include "llvm/Support/VirtualFileSystem.h"
 #include "gtest/gtest.h"
+#include <optional>
 
 namespace clang {
 namespace tooling {
diff --git a/clang/unittests/Tooling/SourceCodeBuildersTest.cpp b/clang/unittests/Tooling/SourceCodeBuildersTest.cpp
index 647ead4..6db3031 100644
--- a/clang/unittests/Tooling/SourceCodeBuildersTest.cpp
+++ b/clang/unittests/Tooling/SourceCodeBuildersTest.cpp
@@ -14,6 +14,7 @@
 #include "llvm/Testing/Support/SupportHelpers.h"
 #include "gmock/gmock.h"
 #include "gtest/gtest.h"
+#include <optional>
 
 using namespace clang;
 using namespace tooling;
diff --git a/clang/unittests/Tooling/StencilTest.cpp b/clang/unittests/Tooling/StencilTest.cpp
index ee77933..68d3a6c 100644
--- a/clang/unittests/Tooling/StencilTest.cpp
+++ b/clang/unittests/Tooling/StencilTest.cpp
@@ -16,6 +16,7 @@
 #include "llvm/Testing/Support/Error.h"
 #include "gmock/gmock.h"
 #include "gtest/gtest.h"
+#include <optional>
 
 using namespace clang;
 using namespace transformer;
diff --git a/clang/unittests/Tooling/Syntax/TokensTest.cpp b/clang/unittests/Tooling/Syntax/TokensTest.cpp
index 1c9cec8..8f15046 100644
--- a/clang/unittests/Tooling/Syntax/TokensTest.cpp
+++ b/clang/unittests/Tooling/Syntax/TokensTest.cpp
@@ -44,6 +44,7 @@
 #include <gmock/gmock.h>
 #include <gtest/gtest.h>
 #include <memory>
+#include <optional>
 #include <ostream>
 #include <string>
 
diff --git a/clang/unittests/Tooling/TransformerTest.cpp b/clang/unittests/Tooling/TransformerTest.cpp
index 4d5e22d..8d10f38 100644
--- a/clang/unittests/Tooling/TransformerTest.cpp
+++ b/clang/unittests/Tooling/TransformerTest.cpp
@@ -17,6 +17,7 @@
 #include "llvm/Support/Error.h"
 #include "gmock/gmock.h"
 #include "gtest/gtest.h"
+#include <optional>
 
 using namespace clang;
 using namespace tooling;
diff --git a/clang/utils/TableGen/ASTTableGen.cpp b/clang/utils/TableGen/ASTTableGen.cpp
index 6aa8b28..79383bf 100644
--- a/clang/utils/TableGen/ASTTableGen.cpp
+++ b/clang/utils/TableGen/ASTTableGen.cpp
@@ -15,6 +15,7 @@
 #include "ASTTableGen.h"
 #include "llvm/TableGen/Record.h"
 #include "llvm/TableGen/Error.h"
+#include <optional>
 
 using namespace llvm;
 using namespace clang;
diff --git a/clang/utils/TableGen/ASTTableGen.h b/clang/utils/TableGen/ASTTableGen.h
index ab9429f3..41f78a6 100644
--- a/clang/utils/TableGen/ASTTableGen.h
+++ b/clang/utils/TableGen/ASTTableGen.h
@@ -11,6 +11,7 @@
 
 #include "llvm/TableGen/Record.h"
 #include "llvm/ADT/STLExtras.h"
+#include <optional>
 
 // These are spellings in the tblgen files.
 
diff --git a/clang/utils/TableGen/ClangASTPropertiesEmitter.cpp b/clang/utils/TableGen/ClangASTPropertiesEmitter.cpp
index c3735f7..3401e03 100644
--- a/clang/utils/TableGen/ClangASTPropertiesEmitter.cpp
+++ b/clang/utils/TableGen/ClangASTPropertiesEmitter.cpp
@@ -20,6 +20,7 @@
 #include "llvm/TableGen/TableGenBackend.h"
 #include <cctype>
 #include <map>
+#include <optional>
 #include <set>
 #include <string>
 using namespace llvm;
diff --git a/clang/utils/TableGen/ClangAttrEmitter.cpp b/clang/utils/TableGen/ClangAttrEmitter.cpp
index 3ae1813..a261cf2 100644
--- a/clang/utils/TableGen/ClangAttrEmitter.cpp
+++ b/clang/utils/TableGen/ClangAttrEmitter.cpp
@@ -37,6 +37,7 @@
 #include <cstdint>
 #include <map>
 #include <memory>
+#include <optional>
 #include <set>
 #include <sstream>
 #include <string>
-- 
2.7.4