Revert "[clang] Convert OptionalFileEntryRefDegradesToFileEntryPtr to std::optional"

This reverts commit 8f0df9f3bbc6d7f3d5cbfd955c5ee4404c53a75d.

The Optional*RefDegradesTo*EntryPtr types want to keep the same size as
the underlying type, which std::optional doesn't guarantee. For use with
llvm::Optional, they define their own storage class, and there is no way
to do that in std::optional.

On top of that, that commit broke builds with older GCCs, where
std::optional was not trivially copyable (static_assert in the clang
sources was failing).

1 files changed, 1 insertions, 2 deletions

diff --git a/clang/lib/Serialization/ModuleManager.cpp b/clang/lib/Serialization/ModuleManager.cpp
index b9fa23b..ae4ea61 100644
--- a/clang/lib/Serialization/ModuleManager.cpp
+++ b/clang/lib/Serialization/ModuleManager.cpp
@@ -35,7 +35,6 @@
 #include <algorithm>
 #include <cassert>
 #include <memory>
-#include <optional>
 #include <string>
 #include <system_error>
 
@@ -445,7 +444,7 @@ void ModuleManager::visit(llvm::function_ref<bool(ModuleFile &M)> Visitor,
 
 bool ModuleManager::lookupModuleFile(StringRef FileName, off_t ExpectedSize,
                                      time_t ExpectedModTime,
-                                     std::optional<FileEntryRef> &File) {
+                                     Optional<FileEntryRef> &File) {
   File = std::nullopt;
   if (FileName == "-")
     return false;