[llvm] [RISCV] Add a pass to remove ADDI by reassociating to fold into load/store address. (PR #127151)

[Philip Reames via llvm-commits]

https://github.com/preames approved this pull request.

LGTM, this is clearly a step forward, but as noted inline, I think we do have at least two items which fall out from this I'd like you to follow up with.  

https://github.com/llvm/llvm-project/pull/127151