[DAG] visitABS - use FoldConstantArithmetic to perform constant folding.

Avoid needing to perform extra isConstantIntBuildVectorOrConstantInt checks

Author: RKSimon

llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp

@@ -10617,8 +10617,8 @@ SDValue DAGCombiner::visitABS(SDNode *N) {
   EVT VT = N->getValueType(0);
 
   // fold (abs c1) -> c2
-  if (DAG.isConstantIntBuildVectorOrConstantInt(N0))
-    return DAG.getNode(ISD::ABS, SDLoc(N), VT, N0);
+  if (SDValue C = DAG.FoldConstantArithmetic(ISD::ABS, SDLoc(N), VT, {N0}))
+    return C;
   // fold (abs (abs x)) -> (abs x)
   if (N0.getOpcode() == ISD::ABS)
     return N0;