[clang] [llvm] [RISCV] Inline Assembly Support for GPR Pairs ('Pr') (PR #112983)

[Sam Elliott via cfe-commits]

lenary wrote:

The commit I just pushed up should be the final version, and not fundamentally different from what was reviewed (but with various NFC patches split out).

I think I do have a route towards merging GPRPair and GPRF64Pair, but I'll do that in a follow-up, as there's a mystery crash somewhere that I haven't tracked down yet.

https://github.com/llvm/llvm-project/pull/112983