Rearrange some methods so that they get inlined.

runtime/vm/native_arguments.cc

Index: runtime/vm/native_arguments.cc
===================================================================
--- runtime/vm/native_arguments.cc	(revision 25803)
+++ runtime/vm/native_arguments.cc	(working copy)
@@ -1,20 +0,0 @@
-// Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
-// for details. All rights reserved. Use of this source code is governed by a
-// BSD-style license that can be found in the LICENSE file.
-
-#include "vm/native_arguments.h"
-
-#include "platform/assert.h"
-#include "vm/object.h"
-
-namespace dart {
-
-void NativeArguments::SetReturn(const Object& value) const {
-  *retval_ = value.raw();
-}
-
-void NativeArguments::SetReturnUnsafe(RawObject* value) const {
-  *retval_ = value;
-}
-
-}  // namespace dart