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

[Matt Arsenault via llvm-commits]

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@@ -699,6 +699,11 @@ bool MachineFunction::needsFrameMoves() const {
          !F.getParent()->debug_compile_units().empty();
 }
 
+/// True if function attribute unsafe-fp-math is true.
+bool MachineFunction::hasUnsafeFPMath() const {
+  return F.getFnAttribute("unsafe-fp-math").getValueAsBool();
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arsenm wrote:

We probably should cache this in a bit in the function instead of requerying the attribute on every use, there are a lot of these. (plus we should stop checking the attributes and move to flags, but that's a bigger ask) 

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