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

[via llvm-commits]

v01dXYZ wrote:

@phoebewang Hi, I hesitate between putting this test in `CodeGen/Generic` or in `CodeGen/X86`. It is some other targets show the same problem.

I'll put it in `CodeGen/X86` as this one won't break the buildbot builds.

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