[clang] [llvm] [RISCV] Add Qualcomm uC Xqcia (Arithmetic) extension (PR #118076)

[Sudharsan Veeravalli via cfe-commits]

svs-quic wrote:

Don't think force push was the right thing to do here. I'll put up another PR. Closing this.

https://github.com/llvm/llvm-project/pull/118076