While the NV extension is totally fine, the KHR extension should be able to support more hardware.
For NVIDIA, the hardware either supports both or neither, it just needs a driver from the last two years.
For AMD, the drivers from late 2022-12 seems to bring support for the KHR extension.
For Intel, the KHR is also supported for some years.
Otherwise, texelFetch() will use an out-of-bounds layer for game textures (that have 1 layer; EFB copies have 2 layers in stereoscopic 3D mode), which is undefined behavior (often resulting in a black image). The fast texture sampling path uses texture(), which always clamps (see https://www.khronos.org/opengl/wiki/Array_Texture#Access_in_shaders), so it was unaffected by this difference.
It stores both the konst selection value for alpha and color channels (for two tev stages per ksel), and half of a swap table row (there are 4 total swap tables, which can be used for swizzling the rasterized color and the texture color, and indices selecting which tables to use are stored per tev stage in the alpha combiner). Since these are indexed very differently, the old code was hard to follow.
Adds a pass to process driver deficiencies between UID caching and use, allowing a full view of the whole pipeline, since some bugs/workarounds involve interactions between blend modes and the pixel shader
