[llvm] [SDAG[[X86] Added method to scalarize `STRICT_FSETCC` (PR #154486)

[Matt Arsenault via llvm-commits]

https://github.com/arsenm approved this pull request.

Wait, vectors of fp80 are allowed? Can we make that a verifier error? Can you test with a real element type? 

https://github.com/llvm/llvm-project/pull/154486