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

[Fangrui Song via llvm-commits]

https://github.com/MaskRay requested changes to this pull request.

Left a comment in in the alternative approach.

I support the changes that eliminate some `MCOp.isBareSymbolRef()` hacks introduced in https://reviews.llvm.org/D45385 (2018). Thanks!
That said, I clicked "request changes" as I strongly recommend that RISC-V avoids adding more hacks to the generic interface like MCInst `MCOperand::isSimpleSymbolRef`.
AsmParser should not check the shape of a `MCExpr`.


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