Auto merge of #127487 - tgross35:f16-f128-simd, r=Amanieu

Add `f16` and `f128` as simd types in LLVM

`@sayantn` is working on adding SIMD for `f16` and hitting the `FloatingPointVector` error. This should fix it and unblock adding support for `simd_fma` and `simd_fabs` in stdarch.