message: Tweak MTL type declarations in metal-cpp.h
  Changes to make metal-cpp options work nicely with RenderDoc serialization
  _MTL_OPTIONS -> _NS_ENUM
  RenderDoc serialization works with fixed sized types
diff: @@ -2376,7 +2376,7 @@ _NS_INLINE const char* NS::URL::fileSystemRepresentation() const
  #define _MTL_CONST(type, name) _NS_CONST(type, name)
  #define _MTL_ENUM(type, name) _NS_ENUM(type, name)
  -#define _MTL_OPTIONS(type, name) _NS_OPTIONS(type, name)
  +#define _MTL_OPTIONS(type, name) _NS_ENUM(type, name)
  #define _MTL_VALIDATE_SIZE(ns, name) _NS_VALIDATE_SIZE(ns, name)
  #define _MTL_VALIDATE_ENUM(ns, name) _NS_VALIDATE_ENUM(ns, name)
  