* 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.
