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

tests/language/call_closurization_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.
-// VMOptions=--optimization_counter_threshold=10
+// VMOptions=--optimization_counter_threshold=10 --no-background_compilation
 
 import "package:expect/expect.dart";
 
 main() {
   bar(a) {
     return a is String;
   }
   var bar_tearOff = bar.call;
 
   for (var i = 0; i < 20; i++) {
@@ skipping 24 matching lines @@
     Expect.equals("4455", named_arg_tearOff(y:55, x:44));
     Expect.equals("4455", named_arg_tearOff.call(y:55, x:44));
     Expect.equals("4455", named_arg_tearOff(x:44, y:55));
     Expect.equals("4455", named_arg_tearOff.call(x:44, y:55));
   }
 
   Expect.throws(() => bar_tearOff.call(), (e) => e is NoSuchMethodError);
   Expect.throws(() => opt_arg_tearOff.call(x:"p"), (e) => e is NoSuchMethodError);
   Expect.throws(() => named_arg_tearOff.call("p", "q"), (e) => e is NoSuchMethodError);
 }