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

tests/language/inline_add_constants_to_initial_env_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.
 // Test that SSA values are correctly numbered after inlining that adds
 // constants to original environment.
-// VMOptions=--optimization-counter-threshold=10
+// VMOptions=--optimization-counter-threshold=10 --no-background-compilation
 
 h(x, y) => x == y;
 
 g(y, [x0 = 0, x1 = 1, x2 = 2, x3 = 3]) => y + x0 + x1 + x2 + x3;
 
 f(y) => h(y, g(y));
 
 main() {
   for (var i = 0; i < 20; i++) f(i);
 }