Fix warnings_checker.dart handling of multitests

tests/language/abstract_runtime_error_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.
 
 import "package:expect/expect.dart";
 
 // Test various conditions around instantiating an abstract class.
 
 // From The Dart Programming Langauge Specification, 11.11.1 "New":
 //   If q is a constructor of an abstract class then an
 //   AbstractClassInstantiation- Error is thrown.
 
 
 abstract class Interface {
-  void foo(); /// 03: static type warning
+  void foo(); //# 03: static type warning
 }
 
 abstract class AbstractClass {
   toString() => 'AbstractClass';
 }
 
 class ConcreteSubclass extends AbstractClass {
   toString() => 'ConcreteSubclass';
 }
 
 class NonAbstractClass implements Interface {
   toString() => 'NonAbstractClass';
 }
 
-Interface interface() => new Interface(); /// 01: static type warning
+Interface interface() => new Interface(); //# 01: static type warning
 
-AbstractClass abstractClass() => new AbstractClass(); /// 02: static type warning
+AbstractClass abstractClass() => new AbstractClass(); //# 02: static type warning
 
 bool isAbstractClassInstantiationError(e) {
   return e is AbstractClassInstantiationError;
 }
 
 void main() {
-  Expect.throws(interface, isAbstractClassInstantiationError, //     /// 01: continued
-                "expected AbstractClassInstantiationError"); //      /// 01: continued
-  Expect.throws(abstractClass, isAbstractClassInstantiationError, // /// 02: continued
-                "expected AbstractClassInstantiationError"); //      /// 02: continued
+  Expect.throws(interface, isAbstractClassInstantiationError, //     //# 01: continued
+                "expected AbstractClassInstantiationError"); //      //# 01: continued
+  Expect.throws(abstractClass, isAbstractClassInstantiationError, // //# 02: continued
+                "expected AbstractClassInstantiationError"); //      //# 02: continued
   Expect.stringEquals('ConcreteSubclass', '${new ConcreteSubclass()}');
   Expect.stringEquals('NonAbstractClass', '${new NonAbstractClass()}');
 }