The new intrinsics we added for doing address calculations are all
things we fetch from the RT_DISPATCH_GLOBALS struct. We could emit an
RT_DISPATCH_GLOBALS load at every point we want it and trust NIR to CSE
it for us but it's easier to use intermediate intrinsics.
Reviewed-by: Caio Marcelo de Oliveira Filho <caio.oliveira@intel.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/7356>
