Add --no-background-compilation to tests that expect to run code in optimized form

tests/language/vm/store_elimination_vm_test.dart

 // 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.
 // Test correctness of side effects tracking used by load to load forwarding.
 
-// VMOptions=--optimization-counter-threshold=10
+// VMOptions=--optimization-counter-threshold=10 --no-background-compilation
 
 import "package:expect/expect.dart";
 
 class C {
   var x;
   var y;
   final z = 123;
 }
 
 class D {
@@ skipping 96 matching lines @@
 test_with_static() {
   for (var i = 0; i < 20; i++) Expect.equals(i + 1, static1(i));
 }
 
 main() {
   test_with_instance();
   test_with_array();
   test_with_context();
   test_with_static();
 }