[llvm] [SelectionDAG] Lower llvm.ldexp.f32 to ldexp() on Windows. (PR #95301)

[Eli Friedman via llvm-commits]

efriedma-quic wrote:

Updated patch to mark "promote". I don't know of any way to do that cross-target, so this is now done per-target; not sure if this is what you expected.

https://github.com/llvm/llvm-project/pull/95301