Fix self-host; ensure signedness is consistent.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@163306 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/ARM/ARMISelLowering.cpp b/lib/Target/ARM/ARMISelLowering.cpp
index 62c7589..5f3a9c7 100644
--- a/lib/Target/ARM/ARMISelLowering.cpp
+++ b/lib/Target/ARM/ARMISelLowering.cpp
@@ -4175,7 +4175,7 @@
 
   // Map of the number of times a particular SDValue appears in the
   // element list.
-  DenseMap<SDValue, int> ValueCounts;
+  DenseMap<SDValue, unsigned> ValueCounts;
   SDValue Value;
   for (unsigned i = 0; i < NumElts; ++i) {
     SDValue V = Op.getOperand(i);
@@ -4187,7 +4187,7 @@
       isConstant = false;
 
     ValueCounts.insert(std::make_pair(V, 0));
-    int &Count = ValueCounts[V];
+    unsigned &Count = ValueCounts[V];
     
     // Is this value dominant? (takes up more than half of the lanes)
     if (++Count > (NumElts / 2)) {