message: Ignore VK_KHR_portability_subset for now.
  This is a temporary workaround to allow running validation with MoltenVK
  even though we do not conform to the portability subset.
diff: @@ -62,6 +62,12 @@ VKAPI_ATTR VkBool32 VKAPI_CALL debugReportCallback(VkDebugReportFlagsEXT flags,
  VKAPI_ATTR VkBool32 VKAPI_CALL debugUtilsCallback(VkDebugUtilsMessageSeverityFlagBitsEXT severity,
  VkDebugUtilsMessageTypeFlagsEXT types, const VkDebugUtilsMessengerCallbackDataEXT* cbdata,
  void* pUserData) {
  + // TODO: this is temporary workaround to allow running validation with MoltenVK
  + // even though we do not conform to the portability subset.
  + if (!strcmp(cbdata->pMessageIdName, "VUID-VkDeviceCreateInfo-pProperties-04451")) {
  + return VK_FALSE;
  + }
  +
  if (severity & VK_DEBUG_UTILS_MESSAGE_SEVERITY_ERROR_BIT_EXT) {
  utils::slog.e << "VULKAN ERROR: (" << cbdata->pMessageIdName << ") "
  << cbdata->pMessage << utils::io::endl;
  