[llvm] [RISCV][GISel] Lower G_SCMP and G_UCMP. (PR #119112)

[Thorsten Schütt via llvm-commits]

tschuett wrote:

SDAG AArch64 is doing both versions based on the type: https://github.com/llvm/llvm-project/pull/108830

https://github.com/llvm/llvm-project/pull/119112