nir/deref: Don't try to compare derefs containing casts
One day, we may want copy_prop_vars or other passes to be able to see through certain types of casts such as when someone casts a uint64_t to a uvec2. However, for now we should just avoid casts all together. Fixes: d8e3edb7 "nir/deref: Support casts and ptr_as_array in..." Tested-by:Jesse Natalie <jenatali@microsoft.com> Reviewed-by:
Caio Marcelo de Oliveira Filho <caio.oliveira@intel.com> Part-of: <mesa/mesa!6072> (cherry picked from commit 611f654f)