Fix warnings_checker.dart handling of multitests

tests/language/const_syntax_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";
 
 main() {
   const f0 = 42;
-  const f1; /// 01: compile-time error
+  const f1; //# 01: compile-time error
   const int f2 = 87;
-  const int f3; /// 02: compile-time error
+  const int f3; //# 02: compile-time error
   Expect.equals(42, f0);
   Expect.equals(87, f2);
 
   Expect.equals(42, F0);
-  Expect.equals(null, F1); /// 03: compile-time error
+  Expect.equals(null, F1); //# 03: compile-time error
   Expect.equals(87, F2);
-  Expect.equals(null, F3); /// 04: compile-time error
+  Expect.equals(null, F3); //# 04: compile-time error
 
   Expect.isTrue(P0 is Point);
-  Expect.isTrue(P1 is int); //  /// 05: compile-time error
-  Expect.isTrue(P2 is Point); /// 06: compile-time error
-  Expect.isTrue(P3 is int); //  /// 07: compile-time error
+  Expect.isTrue(P1 is int); //  //# 05: compile-time error
+  Expect.isTrue(P2 is Point); //# 06: compile-time error
+  Expect.isTrue(P3 is int); //  //# 07: compile-time error
 
   Expect.isTrue(A0 is int);
   Expect.isTrue(A1 is int);
-  Expect.isTrue(A2 is int); /// 08: compile-time error
-  Expect.isTrue(A3 is int); /// 08: continued
+  Expect.isTrue(A2 is int); //# 08: compile-time error
+  Expect.isTrue(A3 is int); //# 08: continued
 
   Expect.isTrue(C0.X is C1);
-  Expect.isTrue(C0.X.x is C1); /// 09: compile-time error
+  Expect.isTrue(C0.X.x is C1); //# 09: compile-time error
 
   Expect.equals("Hello 42", B2);
-  Expect.equals("42Hello", B3); /// 10: compile-time error
+  Expect.equals("42Hello", B3); //# 10: compile-time error
 
   const cf1 = identical(const Point(1, 2), const Point(1, 2));
 
-  const cf2 = identical(const Point(1, 2), new Point(1, 2)); // /// 11: compile-time error
+  const cf2 = identical(const Point(1, 2), new Point(1, 2)); // //# 11: compile-time error
 
-  var f4 = B4; //  /// 12: compile-time error
+  var f4 = B4; //  //# 12: compile-time error
   var f5 = B5;
 }
 
 const F0 = 42;
-const F1; //                /// 03: continued
+const F1; //                //# 03: continued
 const int F2 = 87;
-const int F3; //            /// 04: continued
+const int F3; //            //# 04: continued
 
 class Point {
   final x, y;
   const Point(this.x, this.y);
   operator +(int other) => x;
 }
 
 // Check that compile time expressions can include invocations of
 // user-defined const constructors.
 const P0 = const Point(0, 0);
-const P1 = const Point(0, 0) + 1; /// 05: continued
-const P2 = new Point(0, 0); //      /// 06: continued
-const P3 = new Point(0, 0) + 1; //  /// 07: continued
+const P1 = const Point(0, 0) + 1; //# 05: continued
+const P2 = new Point(0, 0); //      //# 06: continued
+const P3 = new Point(0, 0) + 1; //  //# 07: continued
 
 // Check that we cannot have cyclic references in compile time
 // expressions.
 const A0 = 42;
 const A1 = A0 + 1;
-const A2 = A3 + 1; /// 08: continued
-const A3 = A2 + 1; /// 08: continued
+const A2 = A3 + 1; //# 08: continued
+const A3 = A2 + 1; //# 08: continued
 
 class C0 {
   static const X = const C1();
 }
 
 class C1 {
   const C1()
-      : x = C0.X /// 09: continued
+      : x = C0.X //# 09: continued
   ;
   final x = null;
 }
 
 // Check that sub-expressions of binary + are numeric.
 const B0 = 42;
 const B1 = "Hello";
 const B2 = "$B1 $B0";
-const B3 = B0 + B1; /// 10: continued
+const B3 = B0 + B1; //# 10: continued
 
 // Check identical.
 
-const B4 = identical(1, new Point(1,2)); // /// 12: compile-time error
+const B4 = identical(1, new Point(1,2)); // //# 12: compile-time error
 const B5 = identical(1, const Point(1,2));