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

tests/language/try_catch5_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.
 // Check that our SSA graph does have the try body a predecessor of a
 // try/finally.
-// VMOptions=--optimization-counter-threshold=10
+// VMOptions=--optimization-counter-threshold=10 --no-background-compilation
 
 import "package:expect/expect.dart";
 
 var a;
 
 foo1() {
   var b = false;
   var entered = false;
   while (true) {
     if (entered) return b;
@@ skipping 12 matching lines @@
     }
   }
 }
 
 main() {
   for (var i = 0; i < 20; i++) {
     a = 0;
     Expect.isTrue(foo1());
   }
 }