DAGCombiner: fix use-counting issue when forming zextload

DAGCombiner was counting all uses of a load node  when considering whether it's
worth combining into a zextload. Really, it wants to ignore the chain and just
count real uses.

rdar://problem/13896307

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@185419 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
index 00469b0..1688fc4 100644
--- a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
+++ b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
@@ -2755,7 +2755,7 @@
       ? cast<LoadSDNode>(N0.getOperand(0))
       : cast<LoadSDNode>(N0);
     if (LN0->getExtensionType() != ISD::SEXTLOAD &&
-        LN0->isUnindexed() && N0.hasOneUse() && LN0->hasOneUse()) {
+        LN0->isUnindexed() && N0.hasOneUse() && SDValue(LN0, 0).hasOneUse()) {
       uint32_t ActiveBits = N1C->getAPIntValue().getActiveBits();
       if (ActiveBits > 0 && APIntOps::isMask(ActiveBits, N1C->getAPIntValue())){
         EVT ExtVT = EVT::getIntegerVT(*DAG.getContext(), ActiveBits);