Replace llvm::Optional with std::optional

Author: etcwilde

include/swift/Frontend/CompileJobCacheResult.h

@@ -50,7 +50,7 @@ class CompileJobCacheResult : public llvm::cas::ObjectProxy {
   Output getOutput(size_t I) const;
 
   /// Retrieves a specific output specified by \p Kind, if it exists.
-  llvm::Optional<Output> getOutput(file_types::ID Kind) const;
+  std::optional<Output> getOutput(file_types::ID Kind) const;
 
   /// Print this result to \p OS.
   llvm::Error print(llvm::raw_ostream &OS);

lib/Frontend/CompileJobCacheResult.cpp

@@ -74,15 +74,15 @@ CompileJobCacheResult::Output CompileJobCacheResult::getOutput(size_t I) const {
   return Output{getOutputObject(I), getOutputKind(I)};
 }
 
-Optional<CompileJobCacheResult::Output>
+std::optional<CompileJobCacheResult::Output>
 CompileJobCacheResult::getOutput(file_types::ID Kind) const {
   size_t Count = getNumOutputs();
   for (size_t I = 0; I < Count; ++I) {
     file_types::ID K = getOutputKind(I);
     if (Kind == K)
       return Output{getOutputObject(I), Kind};
   }
-  return None;
+  return {};
 }
 
 Error CompileJobCacheResult::print(llvm::raw_ostream &OS) {