nv50/ir: implement global atomics and handle it for nir

TGSI doesn't have any concept of global memory right now.

Signed-off-by: Karol Herbst <kherbst@redhat.com>
Acked-by: Dave Airlie <airlied@redhat.com>
43 jobs for !2974 with clover_nir_improvements in 15 minutes and 11 seconds (queued for 6 seconds)
merge request