Fix build failure caused by https://reviews.llvm.org/D150352

Fix build failure caused by https://reviews.llvm.org/D150352

This patch fixes the following build error on the clang-ppc64le-rhel bot seen in
in https://lab.llvm.org/buildbot/#/builders/57/builds/26816/steps/5/logs/stdio:

FAILED: tools/clang/tools/extra/clang-tidy/bugprone/CMakeFiles/obj.clangTidyBugproneModule.dir/UncheckedOptionalAccessCheck.cpp.o
.../clang-ppc64le-rhel/llvm-project/clang-tools-extra/clang-tidy/bugprone/UncheckedOptionalAccessCheck.cpp:43:27: error: 'build' is deprecated: Use the version that takes a const Decl & instead [-Werror,-Wdeprecated-declarations]
      ControlFlowContext::build(&FuncDecl, *FuncDecl.getBody(), ASTCtx);
                          ^
.../ppc64le-clang-rhel-test/clang-ppc64le-rhel/llvm-project/clang/include/clang/Analysis/FlowSensitive/ControlFlowContext.h:41:3: note: 'build' has been explicitly marked deprecated here
  LLVM_DEPRECATED("Use the version that takes a const Decl & instead", "")
  ^
.../clang-ppc64le-rhel/llvm-project/llvm/include/llvm/Support/Compiler.h:143:50: note: expanded from macro 'LLVM_DEPRECATED'
#define LLVM_DEPRECATED(MSG, FIX) __attribute__((deprecated(MSG, FIX)))
                                                 ^
1 error generated.