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

tests/language/many_overridden_no_such_method_test.dart

Index: tests/language/many_overridden_no_such_method_test.dart
diff --git a/tests/language/many_overridden_no_such_method_test.dart b/tests/language/many_overridden_no_such_method_test.dart
index a9eb62eb3b9c0e3c9b6e51c48ed897e8fd18508a..e5c32ce5a98bb926fd197ac40d2a1bdc7a370dc0 100644
--- a/tests/language/many_overridden_no_such_method_test.dart
+++ b/tests/language/many_overridden_no_such_method_test.dart
@@ -1,7 +1,7 @@
 // Copyright (c) 2011, 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.
-// VMOptions=--optimization-counter-threshold=10
+// VMOptions=--optimization-counter-threshold=10 --no-background-compilation
 
 library OverriddenNoSuchMethodTest.dart;