[llvm] [RISCV] Teach RISCVMakeCompressible handle Zca/Zcf/Zce/Zcd. (PR #81844)

[Yeting Kuo via llvm-commits]

yetingk wrote:

> Are you planning to follow-up with a patch to teach isCompressibleLoad and isCompressibleStore about half/byte loads+stores where Zcb is available?

Sure. I am willing to do it.

https://github.com/llvm/llvm-project/pull/81844