Add DAG parameter to ComputeNumSignBitsForTargetNode

This way, you can check the number of sign bits in the
operands. The depth parameter it already has is pretty useless
without this.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@205649 91177308-0d34-0410-b5e6-96231b3b80d8

lib/CodeGen/SelectionDAG/TargetLowering.cpp

@@ -1074,6 +1074,7 @@ void TargetLowering::computeMaskedBitsForTargetNode(const SDValue Op,
 /// targets that want to expose additional information about sign bits to the
 /// DAG Combiner.
 unsigned TargetLowering::ComputeNumSignBitsForTargetNode(SDValue Op,
+                                                         const SelectionDAG &,
                                                          unsigned Depth) const {
   assert((Op.getOpcode() >= ISD::BUILTIN_OP_END ||
           Op.getOpcode() == ISD::INTRINSIC_WO_CHAIN ||