Use SmallVectorImpl instead of SmallVector for iterators and references to avoid specifying the vector size unnecessarily.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@185512 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/SelectionDAG/SelectionDAG.cpp b/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
index 5960880..954388d 100644
--- a/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
+++ b/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
@@ -5896,7 +5896,7 @@
       ClonedDVs.push_back(Clone);
     }
   }
-  for (SmallVector<SDDbgValue *, 2>::iterator I = ClonedDVs.begin(),
+  for (SmallVectorImpl<SDDbgValue *>::iterator I = ClonedDVs.begin(),
          E = ClonedDVs.end(); I != E; ++I)
     AddDbgValue(*I, ToNode, false);
 }