Instead of trying to precalculate GEP offsets ahead of time and then
process resource accesses based off of these offsets, traverse the GEP
chain inline for each access. This makes it easier to get the types
correct when translating GEPs for cbuffer and structured buffer
accesses, which in turn lets us access individual elements of those
structures directly.
Fixes#160208, #164517, and #169430
c3039a7dc5