message: Fail early if required extension/feature isn't available
diff: @@ -3035,6 +3035,9 @@ OpMemberDecorate %cbuffer_struct 17 Offset 216 ; double doublePackSource
  VulkanGraphicsTest::Prepare(argc, argv);
  + if(!Avail.empty())
  + return;
  +
  vk_version = 0x10;
  if(physProperties.apiVersion >= VK_MAKE_VERSION(1, 1, 0))
  