[Bitcode] Use std::nullopt instead of None (NFC)

This patch mechanically replaces None with std::nullopt where the
compiler would warn if None were deprecated.  The intent is to reduce
the amount of manual work required in migrating from Optional to
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

1 files changed, 6 insertions, 5 deletions

diff --git a/llvm/lib/Bitcode/Reader/MetadataLoader.cpp b/llvm/lib/Bitcode/Reader/MetadataLoader.cpp
index 1ac1502..fd493a5 100644
--- a/llvm/lib/Bitcode/Reader/MetadataLoader.cpp
+++ b/llvm/lib/Bitcode/Reader/MetadataLoader.cpp
@@ -222,7 +222,7 @@ Metadata *BitcodeReaderMetadataList::getMetadataFwdRef(unsigned Idx) {
 
   // Create and return a placeholder, which will later be RAUW'd.
   ++NumMDNodeTemporary;
-  Metadata *MD = MDNode::getTemporary(Context, None).release();
+  Metadata *MD = MDNode::getTemporary(Context, std::nullopt).release();
   MetadataPtrs[Idx].reset(MD);
   return MD;
 }
@@ -304,7 +304,7 @@ Metadata *BitcodeReaderMetadataList::upgradeTypeRef(Metadata *MaybeUUID) {
 
   auto &Ref = OldTypeRefs.Unknown[UUID];
   if (!Ref)
-    Ref = MDNode::getTemporary(Context, None);
+    Ref = MDNode::getTemporary(Context, std::nullopt);
   return Ref.get();
 }
 
@@ -321,7 +321,7 @@ Metadata *BitcodeReaderMetadataList::upgradeTypeRefArray(Metadata *MaybeTuple) {
   // resolveTypeRefArrays() will be resolve this forward reference.
   OldTypeRefs.Arrays.emplace_back(
       std::piecewise_construct, std::forward_as_tuple(Tuple),
-      std::forward_as_tuple(MDTuple::getTemporary(Context, None)));
+      std::forward_as_tuple(MDTuple::getTemporary(Context, std::nullopt)));
   return OldTypeRefs.Arrays.back().second.get();
 }
 
@@ -1212,7 +1212,8 @@ Error MetadataLoader::MetadataLoaderImpl::parseOneMetadata(
     // If this isn't a LocalAsMetadata record, we're dropping it.  This used
     // to be legal, but there's no upgrade path.
     auto dropRecord = [&] {
-      MetadataList.assignValue(MDNode::get(Context, None), NextMetadataNo);
+      MetadataList.assignValue(MDNode::get(Context, std::nullopt),
+                               NextMetadataNo);
       NextMetadataNo++;
     };
     if (Record.size() != 2) {
@@ -1624,7 +1625,7 @@ Error MetadataLoader::MetadataLoaderImpl::parseOneMetadata(
             DIFile,
             (Context, getMDString(Record[1]), getMDString(Record[2]), Checksum,
              Record.size() > 5 ? Optional<MDString *>(getMDString(Record[5]))
-                               : None)),
+                               : std::nullopt)),
         NextMetadataNo);
     NextMetadataNo++;
     break;