[clang] 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, 1 insertions, 1 deletions

diff --git a/clang/lib/Serialization/ModuleManager.cpp b/clang/lib/Serialization/ModuleManager.cpp
index 544dac1..ae4ea61 100644
--- a/clang/lib/Serialization/ModuleManager.cpp
+++ b/clang/lib/Serialization/ModuleManager.cpp
@@ -445,7 +445,7 @@ void ModuleManager::visit(llvm::function_ref<bool(ModuleFile &M)> Visitor,
 bool ModuleManager::lookupModuleFile(StringRef FileName, off_t ExpectedSize,
                                      time_t ExpectedModTime,
                                      Optional<FileEntryRef> &File) {
-  File = None;
+  File = std::nullopt;
   if (FileName == "-")
     return false;