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

tests/language/bit_operations_test.dart

 // 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.
 // Dart test for testing bitwise operations.
-// VMOptions=--optimization-counter-threshold=10 --no-use-osr
+// VMOptions=--optimization-counter-threshold=10 --no-use-osr --no-background-compilation
 
 import "package:expect/expect.dart";
 
 void main() {
   for (int i = 0; i < 4; i++) {
     test();
   }
 }
 
 void test() {
@@ skipping 170 matching lines @@
   Expect.notEquals((a & b) ^ (c | (d & b)) ^ c, result);    // &|^
   Expect.notEquals((a & b) ^ ((c | d) & b) ^ c, result);    // |&^
   Expect.notEquals(a & (b ^ (c | d)) & (b ^ c), result);    // |^&
   Expect.notEquals(a & ((b ^ c) | d) & (b ^ c), result);    // ^|&
   // Binds stronger than relational operators.
   Expect.equals((a & b) < (c & d), a & b < c & d);
   // Binds weaker than shift operators.
   Expect.equals((a & (b << c)) ^ d, a & b << c ^ d);
   Expect.notEquals((a & b) << (c ^ d), a & b << c ^ d);
 }