Deref handling cleanup
Just one patch on top of !90 (merged) to get rid of the deref handling logic that's no longer needed after the changes we've done to lower the deref chains. I also get rid of load_mem_ubo() which is now replaced by emit_load_ubo_dxil() + a lowering pass to handle complex/sub-32b types.
I ran clc_nir_to_dxil_test and all tests pass, but it'd be better to run piglit before considering merging this patch.
Edited by Boris Brezillon