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

tests/language/instanceof_optimized_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.
 // Testing optimized 'is' tests.
-// VMOptions=--optimization-counter-threshold=5 --no-use-osr
+// VMOptions=--optimization-counter-threshold=5 --no-use-osr --no-background-compilation
 
 import "package:expect/expect.dart";
 
 
 bool isInt(x) => x is int;
 
 
 int isIntRes(x) {
   if (x is int) {
     return 1;
@@ skipping 85 matching lines @@
   for (int i = 0; i < 20; i++) {
     Expect.equals(0, isStringRes(3.2));
     Expect.equals(1, isStringRes("Lotus"));
     Expect.equals(0, isStringRes(null));
 
     Expect.equals(1, isNotStringRes(3.2));
     Expect.equals(0, isNotStringRes("Lotus"));
     Expect.equals(1, isNotStringRes(null));
   }
 }