[llvm] [X86][LegalizeDAG] FPOWI: promote f16 operand (PR #105775)

[via llvm-commits]

v01dXYZ wrote:

There is something I don't understand in `TargetLoweringBase`, some default operation actions are `Expand` but what does it mean to `Expand` with types that are already the smallest ones possible (in our case, that's `f16`).

https://github.com/llvm/llvm-project/pull/105775