ac/llvm: rewrite global & shared stores to share code

The alignment change allows LLVM to select 32-bit stores when 8-bit and
16-bit stores are properly aligned.

Reviewed-by: Rhys Perry <pendingchaos02@gmail.com>
Acked-by: Pierre-Eric Pelloux-Prayer <pierre-eric.pelloux-prayer@amd.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/35950>
1 file changed