Use SmallVectorImpl& for function arguments instead of SmallVector.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@185715 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/AST/VTableBuilder.cpp b/lib/AST/VTableBuilder.cpp
index 6c968bf..69a70a1 100644
--- a/lib/AST/VTableBuilder.cpp
+++ b/lib/AST/VTableBuilder.cpp
@@ -1068,8 +1068,8 @@
   assert(!isBuildingConstructorVTable() && 
          "Can't add thunks for construction vtable");
 
-  SmallVector<ThunkInfo, 1> &ThunksVector = Thunks[MD];
-  
+  SmallVectorImpl<ThunkInfo> &ThunksVector = Thunks[MD];
+
   // Check if we have this thunk already.
   if (std::find(ThunksVector.begin(), ThunksVector.end(), Thunk) != 
       ThunksVector.end())