Fix warnings_checker.dart handling of multitests

tests/language_strong/final_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() {
   final f0 = 42;
-  final f1; /// 01: compile-time error
+  final f1; //# 01: compile-time error
   final int f2 = 87;
-  final int f3; /// 02: compile-time error
+  final 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);
   Expect.isTrue(P2 is Point);
   Expect.isTrue(P3 is int);
 
   Expect.isTrue(A0 is int);
   Expect.isTrue(A1 is int);
-  Expect.isTrue(A2 is int); /// 08: runtime error
-  Expect.isTrue(A3 is int); /// 08: continued
+  Expect.isTrue(A2 is int); //# 08: runtime 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: runtime error
+  Expect.equals("42Hello", B3); //# 10: runtime error
 }
 
 final F0 = 42;
-final F1; //                /// 03: continued
+final F1; //                //# 03: continued
 final int F2 = 87;
-final int F3; //            /// 04: continued
+final 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 final constructors.
 final P0 = const Point(0, 0);
 final P1 = const Point(0, 0) + 1;
 final P2 = new Point(0, 0);
 final P3 = new Point(0, 0) + 1;
 
 // Check that we cannot have cyclic references in compile time
 // expressions.
 final A0 = 42;
 final A1 = A0 + 1;
-final A2 = A3 + 1; /// 08: continued
-final A3 = A2 + 1; /// 08: continued
+final A2 = A3 + 1; //# 08: continued
+final A3 = A2 + 1; //# 08: continued
 
 class C0 {
   static final 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.
 final B0 = 42;
 final B1 = "Hello";
 final B2 = "$B1 $B0";
-final B3 = B0 + B1; /// 10: continued
+final B3 = B0 + B1; //# 10: continued