Throw a type error in production mode when the type of the type test is not

runtime/bin/builtin.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.
 
 #library("builtin");
+#import("dart:uri");
 
 void print(arg) {
   _Logger._printString(arg.toString());
 }
 
 void exit(int status) {
   if (status is !int) {
     throw new IllegalArgumentException("int status expected");
   }
   _exit(status);
@@ skipping 121 matching lines @@
     var wrong = 'package://$path';
 
     throw "URIs using the 'package:' scheme should look like " +
           "'$right', not '$wrong'.";
   }
 
   var path = _entrypoint.resolve('packages/${uri.path}').path;
   _logResolution("# Package: $path");
   return path;
 }