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/cfe/trunk@185610 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Parse/ParseDeclCXX.cpp b/lib/Parse/ParseDeclCXX.cpp
index d630879..67f9c3c 100644
--- a/lib/Parse/ParseDeclCXX.cpp
+++ b/lib/Parse/ParseDeclCXX.cpp
@@ -2243,7 +2243,7 @@
       SmallVector<SourceRange, 4> Ranges;
       DeclaratorInfo.getCXX11AttributeRanges(Ranges);
       if (!Ranges.empty()) {
-        for (SmallVector<SourceRange, 4>::iterator I = Ranges.begin(), 
+        for (SmallVectorImpl<SourceRange>::iterator I = Ranges.begin(),
              E = Ranges.end(); I != E; ++I) {
           Diag((*I).getBegin(), diag::err_attributes_not_allowed) 
             << *I;