[X86] Update SSE/AVX ABS intrinsics to emit llvm.abs.* (PR46851)

We're now getting close to having the necessary analysis/combines etc. for the new generic llvm.abs.* intrinsics.

This patch updates the SSE/AVX ABS vector intrinsics to emit the generic equivalents instead of the icmp+sub+select code pattern.

Differential Revision: https://reviews.llvm.org/D87101