Support typedef type literals

pkg/compiler/lib/src/kernel/env.dart

 // Copyright (c) 2017, 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 dart2js.kernel.env;
 
 import 'package:kernel/ast.dart' as ir;
 import 'package:kernel/clone.dart';
 import 'package:kernel/type_algebra.dart';
 
@@ skipping 575 matching lines @@
       }
     }
     return _constant;
   }
 
   @override
   FieldData copy() {
     return new FieldDataImpl(node, definition);
   }
 }
+
+class TypedefData {
+  final ir.Typedef node;
+  final TypedefEntity element;
+  final TypedefType rawType;
+
+  TypedefData(this.node, this.element, this.rawType);
+}