[llvm] [TLI] Pass replace-with-veclib works with Scalable Vectors. (PR #73642)

[Paschalis Mpeis via llvm-commits]

paschalis-mpeis wrote:

The below functions were not vectorized:

In test `intrinsics-with-veclib-sleef-scalable.ll`:
- `ceil`, `copysign`, `fabs`, `fabs`, `floor`, `fma`, `maxnum`, `minnum`, `nearbyint`, `pow`, `rint`, `round`, `sqrt`, `trunc`
- All 14 of them do not have a vectorized variant (i.e., `isFunctionVectorizable` is false)

In test `replace-intrinsics-with-veclib-armpl.ll`:
- `lvm.pow.*` but this is a known bug for intrinsics which take more than one argument. (site other one?)

https://github.com/llvm/llvm-project/pull/73642