[llvm] [CodeGen] Provide `MachineFunction::hasUnsafeFPMath` (PR #127488)

[Justin Fargnoli via llvm-commits]

https://github.com/justinfargnoli commented:

What's the story for folks that're using `Options.UnsafeFPMath`? Do they need to migrate to using the attribute instead? 

https://github.com/llvm/llvm-project/pull/127488