[llvm] [RISCV] Add ISel patterns for Qualcomm uC Xqcicm extension (PR #145643)

[via llvm-commits]

hchandel wrote:

> Will you be adding commuting support for the rd/rs3 sources? That should avoid some copies if rs3 is a better match for the destination register.

I will do that in a follow-up PR

https://github.com/llvm/llvm-project/pull/145643