[Analysis] Use std::optional in MLInlineAdvisor.h (NFC)

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

llvm/include/llvm/Analysis/MLInlineAdvisor.h

@@ -18,6 +18,7 @@
 #include <deque>
 #include <map>
 #include <memory>
+#include <optional>
 
 namespace llvm {
 class DiagnosticInfoOptimizationBase;
@@ -117,7 +118,7 @@ class MLInlineAdvice : public InlineAdvice {
   // Make a copy of the FPI of the caller right before inlining. If inlining
   // fails, we can just update the cache with that value.
   const FunctionPropertiesInfo PreInlineCallerFPI;
-  Optional<FunctionPropertiesUpdater> FPU;
+  std::optional<FunctionPropertiesUpdater> FPU;
 };
 
 } // namespace llvm