- Harden code_collection_test against GCs happening at unexpected

tests/standalone/io/code_collection_test.dart

 // Copyright (c) 2013, 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 program testing code GC.
 
 import "package:expect/expect.dart";
 import "dart:async";
 import "dart:io";
 
 
 int foo(int x) {
   x = x + 1;
+  print("foo=$x");
   return x;
 }
 
 
 List<int> bar() {
   // A couple of big allocations trigger GC.
   var l = new List.filled(700000, 7);
   return l;
 }
 
 
 doTest() {
   var i = 0;
   var ret = foo(1);  // Initial call to compile.
-  print("foo=$ret");
   // Time passes, GC runs, foo's code is dropped.
   var ms = const Duration(milliseconds: 100);
   var t = new Timer.periodic(ms, (timer) {
     i++;
+    // Calling bar will trigger GC without foo being on the stack. This way
+    // the method can be collected.
     bar();
     if (i > 1) {
       timer.cancel();
       // foo is called again to make sure we can still run it even after
       // its code has been detached.
       var ret = foo(2);
-      print("foo=$ret");
     }
   });
 }
 
 
 main(List<String> arguments) {
   if (arguments.contains("--run")) {
     doTest();
   } else {
     // Run the test and capture stdout.
@@ skipping 24 matching lines @@
         count++;
       }
       if (line.contains("foo=3")) {
         Expect.equals(2, count);
         count++;
       }
     });
     Expect.equals(3, count);
   }
 }