[llvm] [AMDGPU] Sink uniform buffer address offsets into soffset (PR #169230)

[Jay Foad via llvm-commits]

jayfoad wrote:

The claim here is that for raw buffer operations there is no semantic reason to separate out the voffset/soffset/immediate parts of the offset. So a more comprehensive implementation would be to canonicalize them as early as possible with a single offset operand which is the sum of the three offsets provided by the programmer. Then instruction selection can split that back into divergent/uniform/constant parts like we already do for lots of addressing modes.

https://github.com/llvm/llvm-project/pull/169230