Fix warnings_checker.dart handling of multitests

tests/language_strong/number_identifier_test.dart

 // Copyright (c) 2011, 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() {
   // Integer literals.
   Expect.isTrue(2is int);
   Expect.equals(2, 2as int);
   Expect.isTrue(-2is int);
   Expect.equals(-2, -2as int);
   Expect.isTrue(0x10is int);
   Expect.isTrue(-0x10is int);
   // "a" will be part of hex literal, the following "s" is an error.
-  0x10as int; // /// 01: compile-time error
-  0x; //         /// 04: compile-time error
+  0x10as int; // //# 01: compile-time error
+  0x; //         //# 04: compile-time error
 
   // Double literals.
   Expect.isTrue(2.0is double);
   Expect.equals(2.0, 2.0as double);
   Expect.isTrue(-2.0is double);
   Expect.equals(-2.0, -2.0as double);
   Expect.isTrue(.2is double);
   Expect.equals(0.2, .2as double);
   Expect.isTrue(1e2is double);
   Expect.equals(1e2, 1e2as double);
   Expect.isTrue(1e-2is double);
   Expect.equals(1e-2, 1e-2as double);
   Expect.isTrue(1e+2is double);
   Expect.equals(1e+2, 1e+2as double);
-  Expect.throws(() => 1.e+2, //                      /// 05: ok
-                (e) => e is NoSuchMethodError); //   /// 05: continued
-  1d; // /// 06: compile-time error
-  1D; // /// 07: compile-time error
-  Expect.throws(() => 1.d+2, //                      /// 08: ok
-                (e) => e is NoSuchMethodError); //   /// 08: continued
-  Expect.throws(() => 1.D+2, //                      /// 09: ok
-                (e) => e is NoSuchMethodError); //   /// 09: continued
-  1.1d; // /// 10: compile-time error
-  1.1D; // /// 11: compile-time error
-  1e; // /// 02: compile-time error
-  1x; // /// 03: compile-time error
+  Expect.throws(() => 1.e+2, //                      //# 05: ok
+                (e) => e is NoSuchMethodError); //   //# 05: continued
+  1d; // //# 06: compile-time error
+  1D; // //# 07: compile-time error
+  Expect.throws(() => 1.d+2, //                      //# 08: ok
+                (e) => e is NoSuchMethodError); //   //# 08: continued
+  Expect.throws(() => 1.D+2, //                      //# 09: ok
+                (e) => e is NoSuchMethodError); //   //# 09: continued
+  1.1d; // //# 10: compile-time error
+  1.1D; // //# 11: compile-time error
+  1e; // //# 02: compile-time error
+  1x; // //# 03: compile-time error
 }