Height can be equal, just not greater.

Oops.
Destroy all FBOs/textures upon sceKernelLoadExec().

It can confuse our heuristics about size, attachment, memcpy, etc.
Revert the early wake of threads for io waits.

This reverts commit 610ada87214c60a8e5b1f5f742135abbc5cf2544.

It makes sense to let these run longer.  Apparently this caused problems
in Castlevania, see #6432.
Allow rescheduling within callbacks.
Remove outdated comment (real cause found/fixed.)
Simplify __KernelReSchedule().

It no longer needs all these checks, and we can Advance within callbacks,
interrupts, etc. safely.
Avoid Advance() twice, cleanup some comments.
Merge pull request #6452 from unknownbrackets/callbacks

Allow rescheduling within a callback
Merge pull request #6450 from unknownbrackets/gpu-blocktransfer

Clear framebuffers/textures upon sceKernelLoadExec()