Background compilation work:

tests/language/vm/load_elimination_two_redefinitions_test.dart

 // Copyright (c) 2014, 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 correctness of side effects tracking used by load to load forwarding.
 
-// VMOptions=--optimization-counter-threshold=10 --no-use-osr --enable-inlining-annotations
+// VMOptions=--optimization-counter-threshold=10 --no-use-osr --enable-inlining-annotations --no-background-compilation
 
 // Tests correct handling of redefinitions in aliasing computation.
 
 import "package:expect/expect.dart";
 
 const alwaysInline = "AlwaysInline";
 const noInline = "NeverInline";
 
 var H = true;
 
@@ skipping 33 matching lines @@
 }
 
 main() {
   // Prime foo with polymorphic type feedback.
   foo(new B(), new A());
   foo(new A(), new B());
 
   for (var i = 0; i < 100; i++) test();
   Expect.equals(123, test());
 }