message: Fix warning about macro expansion.
diff: // } } }
  //
  // Validation crashes on MoltenVK, so we disable it by default on MacOS.
  -#define ENABLE_VALIDATION (!defined(NDEBUG) && !defined(__APPLE__))
  +#if !defined(NDEBUG) && !defined(__APPLE__)
  +#define ENABLE_VALIDATION 1
  +#else
  +#define ENABLE_VALIDATION 0
  +#endif
  #if ENABLE_VALIDATION
  