All the same formula: calculate an address, emit a pseudoinstruction for
the atomic, emit a postprocess that can be DCE'd if not needed.
Signed-off-by: Alyssa Rosenzweig <alyssa.rosenzweig@collabora.com>
Tested-by: Icecream95 <ixn@disroot.org>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/9105>