Fix warnings_checker.dart handling of multitests

tests/lib_strong/mirrors/parameter_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.
 
 // This tests uses the multi-test "ok" feature:
 // none: Desired behaviour, passing on the VM.
 // 01: Trimmed version for dart2js.
 //
 // TODO(rmacnak,ahe): Remove multi-test when VM and dart2js are on par.
 
@@ skipping 61 matching lines @@
   expect('Method(s(B.bar) in s(B), constructor)', barConstructor);
   expect('[Parameter(s(z) in s(B.bar),'
          ' type = Class(s(int) in s(dart.core), top-level)), '
          'Parameter(s(x) in s(B.bar),'
          ' type = Type(s(dynamic), top-level))]',
          barConstructor.parameters);
   expect('Class(s(B) in s(test.parameter_test), top-level)',
          barConstructor.returnType);
 
   // dart2js stops testing here.
-  return; // /// 01: ok
+  return; // //# 01: ok
 
   MethodMirror bazConstructor = constructors[#B.baz];
   expect('Method(s(B.baz) in s(B), constructor)', bazConstructor);
   expect('[Parameter(s(x) in s(B.baz), final,'
          ' type = Class(s(int) in s(dart.core), top-level)), '
          'Parameter(s(y) in s(B.baz),'
          ' type = Class(s(int) in s(dart.core), top-level)), '
          'Parameter(s(z) in s(B.baz), final,'
          ' type = Class(s(int) in s(dart.core), top-level))]',
          bazConstructor.parameters);
@@ skipping 81 matching lines @@
   expect('[Parameter(s(a) in s(bar),'
          ' type = TypeVariable(s(S) in s(C),'
          ' upperBound = Class(s(int) in s(dart.core), top-level))), '
          'Parameter(s(b) in s(bar),'
          ' type = TypeVariable(s(T) in s(C),'
          ' upperBound = Class(s(Object) in s(dart.core), top-level))), '
          'Parameter(s(c) in s(bar),'
          ' type = Class(s(num) in s(dart.core), top-level))]',
          barInC.parameters);
 }