Fix warnings_checker.dart handling of multitests

tests/language/type_variable_conflict_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.
 
 // Test that we report a compile-time error when a type parameter conflicts
 // with an instance or static member with the same name.
 
 import "package:expect/expect.dart";
 
 class G1<T> {
-  var T; // /// 01: compile-time error
+  var T; // //# 01: compile-time error
 }
 class G2<T> {
-  get T {} // /// 02: compile-time error
+  get T {} // //# 02: compile-time error
 }
 class G3<T> {
-  T() {} // /// 03: compile-time error
+  T() {} // //# 03: compile-time error
 }
 class G4<T> {
-  static var T; // /// 04: compile-time error
+  static var T; // //# 04: compile-time error
 }
 class G5<T> {
-  static get T {} // /// 05: compile-time error
+  static get T {} // //# 05: compile-time error
 }
 class G6<T> {
-  static T() {} // /// 06: compile-time error
+  static T() {} // //# 06: compile-time error
 }
 
 main() {
   new G1<int>();
   new G2<int>();
   new G3<int>();
   new G4<int>();
   new G5<int>();
   new G6<int>();
 }