[llvm] 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, 2 insertions, 2 deletions

diff --git a/llvm/lib/Support/RISCVISAInfo.cpp b/llvm/lib/Support/RISCVISAInfo.cpp
index ff9525b..2be381d 100644
--- a/llvm/lib/Support/RISCVISAInfo.cpp
+++ b/llvm/lib/Support/RISCVISAInfo.cpp
@@ -168,7 +168,7 @@ findDefaultVersion(StringRef ExtName) {
     }
     return ExtensionInfoIterator->Version;
   }
-  return None;
+  return std::nullopt;
 }
 
 void RISCVISAInfo::addExtension(StringRef ExtName, unsigned MajorVersion,
@@ -209,7 +209,7 @@ isExperimentalExtension(StringRef Ext) {
   auto ExtIterator =
       llvm::find_if(SupportedExperimentalExtensions, FindByName(Ext));
   if (ExtIterator == std::end(SupportedExperimentalExtensions))
-    return None;
+    return std::nullopt;
 
   return ExtIterator->Version;
 }