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

tests/language/double_int_addition_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.
-// VMOptions=--optimization-counter-threshold=10 --no-use-osr
+// VMOptions=--optimization-counter-threshold=10 --no-use-osr --no-background-compilation
 
 import "package:expect/expect.dart";
 
 // Test that optimized code does not silently convert integers to doubles.
 
 
 main() {
   // Optimize add-op
   for (int i = 0; i < 20; i++) {
     addOp(1.1, 2.1);
   }
 
   Expect.isTrue(addOp(1.1, 2.1) is double);
   Expect.isTrue(addOp(1, 2) is int);
 }
 
 addOp(a, b) => a + b;