instantiate generic tear-offs, fixes #525

tool/input_sdk/private/ddc_runtime/rtti.dart

 // Copyright (c) 2015, 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.
 
 /// This library defines the association between runtime objects and
 /// runtime types.
 part of dart._runtime;
 
 ///
 /// Runtime type information.  This module defines the mapping from
@@ skipping 130 matching lines @@
   // Fallback on constructor for class types
   result = $obj.constructor;
   if (result == Function) {
     // An undecorated Function should have come from
     // JavaScript.  Treat as untyped.
     return $jsobject;
   }
   return result;
 })()''');
 
-read(value) => JS('', '#[#]', value, _runtimeType);
+_getRuntimeType(value) => JS('', '#[#]', value, _runtimeType);
 
 /// Tag the runtime type of [value] to be type [t].
 void tag(value, t) {
   JS('', '#[#] = #', value, _runtimeType, t);
 }
 
 void tagComputed(value, compute) {
   JS('', '#(#, #, { get: # })', defineProperty, value, _runtimeType, compute);
 }
 
 void tagLazy(value, compute) {
   JS('', '#(#, #, { get: # })',
       defineLazyProperty, value, _runtimeType, compute);
 }