[llvm] [RISCV] custom scmp(x, 0) and scmp(0, x) lowering for RVV (PR #151753)

[Olaf Bernstein via llvm-commits]

camel-cdr wrote:

I initially had a mistake in the conversion, it should now match the alive2 code.

https://github.com/llvm/llvm-project/pull/151753