* Implement RasterizeEnable
* Match viewport count to hardware
* Simplify ScissorTest tracking around Blits
* Disable RasterizerDiscard around Blits and track its state
* Read RasterizeEnable reg as bool and add doc
* Only enumarate cached textures that are modified when flushing, rather than all of them.
* Remove locking.
* Add missing clear.
* Remove texture from modified list when data is disposed.
In case the game does not call either flush method at any point.
* Add ReferenceEqualityComparer from jD for the HashSet
Support shared color masks (used by Nouveau and maybe the NVIDIA
driver).
Support draw buffers (also required by OpenGL).
Support viewport transform disable (disabled for now as it breaks some
games).
Fix instanced rendering draw being ignored for multi draw.
Fix IADD and IADD3 immediate shader encodings, that was not matching
some ops.
Implement FFMA32I shader instruction.
Implement IMAD shader instruction.