[llvm] [llvm][GISel] Use computeKnownFPClass (PR #141484)

[Matt Arsenault via llvm-commits]

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@@ -337,11 +337,12 @@ bool isKnownToBeAPowerOfTwo(Register Val, const MachineRegisterInfo &MRI,
 /// Returns true if \p Val can be assumed to never be a NaN. If \p SNaN is true,
 /// this returns if \p Val can be assumed to never be a signaling NaN.
 bool isKnownNeverNaN(Register Val, const MachineRegisterInfo &MRI,
-                     bool SNaN = false);
+                     GISelValueTracking *ValueTracking, bool SNaN = false);
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arsenm wrote:

If this is optional it should be default initialized to null. If it's required it should be a reference. It should probably be required? 

https://github.com/llvm/llvm-project/pull/141484