[llvm] [X86] Fold vgf2p8affineqb XOR with splat constant into immediate (PR #179103)

[Simon Pilgrim via llvm-commits]

================
@@ -55946,6 +55976,8 @@ static SDValue combineXor(SDNode *N, SelectionDAG &DAG,
 
   if (SDValue RV = foldXorTruncShiftIntoCmp(N, DL, DAG))
     return RV;
+  if (SDValue R = combineXorWithGF2P8AFFINEQB(N, DAG, Subtarget))
----------------
RKSimon wrote:

You should be able to pass in SDLoc to avoid having to create it again:
```suggestion
  if (SDValue R = combineXorWithGF2P8AFFINEQB(N, DL, DAG))
```

https://github.com/llvm/llvm-project/pull/179103