Fix warnings_checker.dart handling of multitests

tests/language/syncstar_yield_test.dart

 // Copyright (c) 2015, 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.
 
 import "package:expect/expect.dart";
 
 Iterable<int> foo1() sync* {
   yield 1;
 }
 
@@ skipping 22 matching lines @@
   p++;
   yield p + i;
 }
 
 main() {
   Expect.listEquals([1], foo1().toList());
   Expect.listEquals([null, -1, 0, 1, 2, 3, 0, 1, 2, 3],
       foo2(4).take(10).toList());
   Iterable t = foo3(0);
   Iterator it1 = t.iterator;
-  Iterator it2 = t.iterator; /// copyParameters: ok
+  Iterator it2 = t.iterator; //# copyParameters: ok
   it1.moveNext();
-  it2.moveNext(); /// copyParameters: continued
+  it2.moveNext(); //# copyParameters: continued
   Expect.equals(2, it1.current);
   // TODO(sigurdm): Check up on the spec here.
-  Expect.equals(2, it2.current); // /// copyParameters: continued
+  Expect.equals(2, it2.current); // //# copyParameters: continued
   Expect.isFalse(it1.moveNext());
   // Test that two `moveNext()` calls are fine.
   Expect.isFalse(it1.moveNext());
-  Expect.isFalse(it2.moveNext()); /// copyParameters: continued
-  Expect.isFalse(it2.moveNext()); /// copyParameters: continued
+  Expect.isFalse(it2.moveNext()); //# copyParameters: continued
+  Expect.isFalse(it2.moveNext()); //# copyParameters: continued
 }