* It's not particularly scalable and can be brittle to driver changes, and we
can use targeted specific pixel tests to check what we really want - to see if
the output has rendered correctly.
* Overlay tests still check files directly - this is a future refactor to
remove.
* Instead of tracking their lifetime with that object, we move the lifetime
tracking into the parent VulkanGraphicsTest and destroy them all at the end. A
single handle can optionally be free'd on its own.
* Visual assist comes with a pre-defined interpretation of TEST() for
googletest, which conflicts with ours. We can't seem to override it with a
va_stdafx.h even
* Instead of patching e.g. PRESENT to GENERAL early, we keep the 'real' layout
even if that's UNDEFINED or PRESENT or whatever. We then do a last-second
patchup whenever we're actually transitioning images in vulkan itself, to set
the right layout.
* This requires us to do the patching in a few more places - anywhere like
texture rendering or initial states where we want to go from current state ->
custom state -> back to current state.
* This also allows us to more gracefully handle PREINITIALIZED image layouts. We
internally promote them to GENERAL as soon as possible, but keep them around
as PREINITIALIZED for display.