[llvm] [RISCV] Add OR/XOR/SUB to RISCVInstrInfo::isCopyInstrImpl (PR #132002)

[Philip Reames via llvm-commits]

preames wrote:

One aside here: The need to handle all these cases hints we have a canonicalization problem.  All of these should be canonicalized into a single instruction.  Unless having them in the isCopyInstrImpl enables that canonicalization - I haven't checked - we might have something to follow up on.  

https://github.com/llvm/llvm-project/pull/132002