Use SmallVectorImpl::iterator/const_iterator instead of SmallVector to avoid specifying the vector size.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@185606 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Transforms/Utils/BasicBlockUtils.cpp b/lib/Transforms/Utils/BasicBlockUtils.cpp
index ba99d2e..9167795 100644
--- a/lib/Transforms/Utils/BasicBlockUtils.cpp
+++ b/lib/Transforms/Utils/BasicBlockUtils.cpp
@@ -170,7 +170,7 @@
       if (DomTreeNode *DTN = DT->getNode(BB)) {
         DomTreeNode *PredDTN = DT->getNode(PredBB);
         SmallVector<DomTreeNode*, 8> Children(DTN->begin(), DTN->end());
-        for (SmallVector<DomTreeNode*, 8>::iterator DI = Children.begin(),
+        for (SmallVectorImpl<DomTreeNode *>::iterator DI = Children.begin(),
              DE = Children.end(); DI != DE; ++DI)
           DT->changeImmediateDominator(*DI, PredDTN);