Simplify CxxValueSemanticsKind

include/swift/ClangImporter/ClangImporterRequests.h

@@ -575,15 +575,7 @@ SourceLoc extractNearestSourceLoc(EscapabilityLookupDescriptor desc);
 // When a reference type is copied, the pointer’s value is copied rather than
 // the object’s storage. This means reference types can be imported as
 // copyable to Swift, even when they are non-copyable in C++.
-enum class CxxValueSemanticsKind {
-  Unknown,
-  Copyable,
-  MoveOnly,
-  // A record that is either not copyable/movable or not destructible.
-  MissingLifetimeOperation,
-  // A record that has no copy and no move operations
-  UnavailableConstructors,
-};
+enum class CxxValueSemanticsKind { Unknown, Copyable, MoveOnly };
 
 struct CxxValueSemanticsDescriptor final {
   const clang::Type *type;