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

runtime/tests/vm/dart/byte_array_optimized_test.dart

Index: runtime/tests/vm/dart/byte_array_optimized_test.dart
diff --git a/runtime/tests/vm/dart/byte_array_optimized_test.dart b/runtime/tests/vm/dart/byte_array_optimized_test.dart
index 8492798724a381e93e1c20d795d363ae0d001d1a..755c3b1b6d7ef6ad165c9ff1f104ba13ce5836c1 100644
--- a/runtime/tests/vm/dart/byte_array_optimized_test.dart
+++ b/runtime/tests/vm/dart/byte_array_optimized_test.dart
@@ -1,7 +1,7 @@
 // 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.
-// VMOptions=--optimization_counter_threshold=10
+// VMOptions=--optimization_counter_threshold=10 --no-background-compilation
 
 // Library tag to be able to run in html test framework.
 library byte_array_test;