[llvm] [SDAG] Merge multiple-result libcall expansion into DAG.expandMultipleResultFPLibCall() (PR #114792)

[Sander de Smalen via llvm-commits]

https://github.com/sdesmalen-arm approved this pull request.

I don't know if there's any better to suggest for the CopyFromReg that is optimised away when it has no uses, but it doesn't seem to break or regress anything either. So overall LGTM.

https://github.com/llvm/llvm-project/pull/114792