[llvm] [AMDGPU] Quiet signaling NaN when constant-folding CLAMP (PR #207902)

[Arseniy Obolenskiy via llvm-commits]

================
@@ -18503,6 +18503,9 @@ SDValue SITargetLowering::performClampCombine(SDNode *N,
   if (F > One)
     return DCI.DAG.getConstantFP(One, SDLoc(N), N->getValueType(0));
 
+  if (F.isSignaling())
----------------
aobolensk wrote:

I have tried routing through getCanonicalConstantFP, but it makes existing v_clamp_constant_preserve_denorm_f32 test failed due to the fact that 0x7fffff is being folded to just 0. I'm not sure this is a good way or maybe I'm missing something 

https://github.com/llvm/llvm-project/pull/207902