nir: add load/store variants accepting a 32-bit offset
This is useful for etnaviv, but some other drivers might also be able to make use of it, since both freedreno and amd have their own load/store+offset variants.
cc @gfxstrand
This is useful for etnaviv, but some other drivers might also be able to make use of it, since both freedreno and amd have their own load/store+offset variants.
cc @gfxstrand