Make sure to bind a method to its receiver if it is stored in a temporary.

tests/language/async_this_bound_test.dart

 // Copyright (c) 2015, 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.
 
-// Test that an async function does not start immediately.
-
 import "package:expect/expect.dart";
 import "package:async_helper/async_helper.dart";
 
-var x = 0;
+class A {
+  int a = -1;
+  foo(ignored) {
+    (){};
+    Expect.equals(-1, a);
+  }
+}
 
-foo() async {
-  x++;
-  await 1;
-  x++;
+test() async {
+  new A().foo(await false);
 }
 
 void main() {
   asyncStart();
-  foo().then((_) => Expect.equals(2, x)).whenComplete(asyncEnd);
-  Expect.equals(0, x);
+  test().then((_) => asyncEnd());
 }