Approximately three or four times now, the issue of pointers being
in an inconsistent state been an issue in the video backend renderers
with regards to tripping up other developers.
Global (ugh) resources are put into a unique_ptr and will always have a
well-defined state of being - null or not null
Texture updates have been moved into TextureCache, while
TMEM updates where moved into bpmem. Code for handling
efb2ram updates was added to TextureCache.
There was a bug for preloaded RGBA8 textures, it only copied
half the texture. The TODO was wrong too.
This checks every TEXTURE_KILL_THRESHOLD frames, to see if the hash for the memory area of the efb copy has hanged. If it has changed, the efb copy can be removed, it wouldn't be used anymore. Before this pr, some efb copies would never be deleted.
Fixes issue https://bugs.dolphin-emu.org/issues/6101 and possibly some other VRAM leaks.
Instead of having special case code for efb2tex that ignores hashes,
the only diffence between efb2tex and efb2ram now is that efb2tex
writes zeros to the memory instead of actual texture data.
Though keep in mind, all efb2tex copies will have hashes of zero as
their hash.
Addded a few duplicated depth copy texture formats to the enum
in TextureDecoder.h. These texture formats were already implemented
in TextureCacheBase and the ogl/dx11 texture cache implementations.
