CL: Rework load/store alignment to be on derefs instead of intrinsics
This is based on !299 (merged).
This is a revert of !159 (merged) (which was staged upstream as mesa/mesa!5900 (closed)), and a revert of a couple commits from !116 (merged). Then it picks mesa/mesa!6090 (merged) and mesa/mesa!6472 (merged). Lastly, it adds a couple patches to deal with the alignment info coming in on derefs instead of intrinsics.