Fix handling of inline JS types in DDC.

pkg/dev_compiler/tool/input_sdk/private/js_helper.dart

 // Copyright (c) 2013, 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 dart._js_helper;
 
 import 'dart:collection';
 
 import 'dart:_debugger' show stackTraceMapper;
 
@@ skipping 606 matching lines @@
   String toString() => _message.isEmpty ? 'Error' : 'Error: $_message';
 }
 
 /**
  * Called by generated code to fetch the stack trace from a Dart
  * exception. Should never return null.
  */
 final _stackTrace = JS('', 'Symbol("_stackTrace")');
 StackTrace getTraceFromException(exception) {
   var error = JS('', 'dart.recordJsError(#)', exception);
-  var trace = JS('StackTrace', '#[#]', error, _stackTrace);
+  var trace = JS('StackTrace|Null', '#[#]', error, _stackTrace);
   if (trace != null) return trace;
   trace = new _StackTrace(error);
   JS('', '#[#] = #', error, _stackTrace, trace);
   return trace;
 }
 
 class _StackTrace implements StackTrace {
   var _exception;
   String _trace;
 
@@ skipping 277 matching lines @@
   // we have no way of telling the compiler yet, so it will generate an extra
   // layer of indirection that wraps the SyncIterator.
   _jsIterator() => JS('', '#(...#)', _generator, _args);
 
   Iterator<E> get iterator => new SyncIterator<E>(_jsIterator());
 }
 
 class BooleanConversionAssertionError extends AssertionError {
   toString() => 'Failed assertion: boolean expression must not be null';
 }