Vulkan Validation Errors During Instance Creation Don't Cause Test Failures

[jimblandy]

The transcript in #4037 shows a test run getting a Vulkan validation error reported against it, yet the test still passes. This could mean that our CI is missing validation failures.

[jimblandy]

@cwfitzgerald sagely observes:

of course, we add our validation layer hook in Instance::from_raw, which happens after the instance is created

[jimblandy]

It is actually possible to capture these events: https://registry.khronos.org/vulkan/specs/1.2-extensions/html/vkspec.html#_examples_10

To capture events that occur while creating or destroying an instance, an application can link a VkDebugReportCallbackCreateInfoEXT structure or a VkDebugUtilsMessengerCreateInfoEXT structure to the pNext element of the VkInstanceCreateInfo structure given to vkCreateInstance. This callback is only valid for the duration of the vkCreateInstance and the vkDestroyInstance call. Use vkCreateDebugReportCallbackEXT or vkCreateDebugUtilsMessengerEXT to create persistent callback objects.