[Support] Use std::optional in GenericDomTreeConstruction.h (NFC)

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

diff --git a/llvm/include/llvm/Support/GenericDomTreeConstruction.h b/llvm/include/llvm/Support/GenericDomTreeConstruction.h
index f59151e..2e7716c 100644 (file)
--- a/llvm/include/llvm/Support/GenericDomTreeConstruction.h
+++ b/llvm/include/llvm/Support/GenericDomTreeConstruction.h
@@ -44,6 +44,7 @@
 #include "llvm/ADT/SmallPtrSet.h"
 #include "llvm/Support/Debug.h"
 #include "llvm/Support/GenericDomTree.h"
+#include <optional>
 #include <queue>
 
 #define DEBUG_TYPE "dom-tree-builder"
@@ -403,7 +404,7 @@ struct SemiNCAInfo {
       // immune to swap successors transformation (e.g. canonicalizing branch
       // predicates). SuccOrder is initialized lazily only for successors of
       // reverse unreachable nodes.
-      Optional<NodeOrderMap> SuccOrder;
+      std::optional<NodeOrderMap> SuccOrder;
       auto InitSuccOrderOnce = [&]() {
         SuccOrder = NodeOrderMap();
         for (const auto Node : nodes(DT.Parent))