SmallVector<3> may be used here.

llvm-svn: 204915
diff --git a/llvm/unittests/IR/InstructionsTest.cpp b/llvm/unittests/IR/InstructionsTest.cpp
index e040065..5883e13 100644
--- a/llvm/unittests/IR/InstructionsTest.cpp
+++ b/llvm/unittests/IR/InstructionsTest.cpp
@@ -65,7 +65,7 @@
 
   LLVMContext Ctx;
   std::unique_ptr<Module> M;
-  std::vector<Type *> FArgTypes;
+  SmallVector<Type *, 3> FArgTypes;
   Function *F;
 };