Use SmallVectorImpl& instead of SmallVector to avoid repeating small vector size.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@186284 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/CGObjCGNU.cpp b/lib/CodeGen/CGObjCGNU.cpp
index fbf8a1a..2fd379d 100644
--- a/lib/CodeGen/CGObjCGNU.cpp
+++ b/lib/CodeGen/CGObjCGNU.cpp
@@ -1041,7 +1041,7 @@
 llvm::Value *CGObjCGNU::GetSelector(CodeGenFunction &CGF, Selector Sel,
     const std::string &TypeEncoding, bool lval) {
 
-  SmallVector<TypedSelector, 2> &Types = SelectorTable[Sel];
+  SmallVectorImpl<TypedSelector> &Types = SelectorTable[Sel];
   llvm::GlobalAlias *SelValue = 0;