[llvm] [RISCV] Align MCOperandPredicates with AsmParser (PR #146184)

[Sam Elliott via llvm-commits]

lenary wrote:

@MaskRay https://github.com/llvm/llvm-project/pull/146763 is the alternative implementation, as described. Turns out, the MCOperandPredicates are still a problem, but in a totally different way. There's a long comment in `RISCVInstrInfoXqci.td` on that PR explaining how the PR works.

https://github.com/llvm/llvm-project/pull/146184