[llvm] [llvm] Ensure that soft float targets don't emit `fma()` libcalls. (PR #106615)

[Matt Arsenault via llvm-commits]

https://github.com/arsenm commented:

This doesn't feel like the right place for this, I would expect there to be some legality check that would fail. But there's already precedent for directly handling it here 

https://github.com/llvm/llvm-project/pull/106615