[llvm] [RISCV] Fold vmnot.m of an integer compare into the compare (PR #222553)

[Marton Moro via llvm-commits]

martonmoro wrote:

> Thanks, can you precommit the tests in this PR into a separate commit so the second commit shows the diffs? See https://llvm.org/docs/InstCombineContributorGuide.html#precommit-tests

Ofc, will do soon!

https://github.com/llvm/llvm-project/pull/222553