[X86] X86DAGToDAGISel::matchIndexRecursively - replace hard coded recursion limit with SelectionDAG::MaxRecursionDepth. NFCI.

Author: RKSimon

llvm/lib/Target/X86/X86ISelDAGToDAG.cpp

@@ -2700,7 +2700,7 @@ bool X86DAGToDAGISel::matchVectorAddressRecursively(SDValue N,
     AM.dump(CurDAG);
   });
   // Limit recursion.
-  if (Depth > 5)
+  if (Depth >= SelectionDAG::MaxRecursionDepth)
     return matchAddressBase(N, AM);
 
   // TODO: Support other operations.