[llvm] Enable custom lowering of fabs_v16f16 with AVX and fabs_v32f16 with A… (PR #73565)

[Simon Pilgrim via llvm-commits]

RKSimon wrote:

> This is the last patch for fabs lowering. v32f16 works for AVX as well with the patch (with type legalization).

AVX512 v32f16 still looks very poor

https://github.com/llvm/llvm-project/pull/73565