Do not add type information to constants with constructor taking type information

pkg/compiler/lib/src/js_backend/constant_emitter.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.
 
 import '../common.dart';
 import '../compiler.dart' show Compiler;
 import '../constants/values.dart';
 import '../dart_types.dart';
 import '../elements/elements.dart';
 import '../io/code_output.dart';
@@ skipping 297 matching lines @@
     jsAst.Expression constructor =
         backend.emitter.constructorAccess(constant.type.element);
     List<jsAst.Expression> fields = <jsAst.Expression>[];
     element.forEachInstanceField((_, FieldElement field) {
       fields.add(constantReferenceGenerator(constant.fields[field]));
     }, includeSuperAndInjectedMembers: true);
     if (backend.classNeedsRtiField(constant.type.element)) {
       fields.add(_reifiedTypeArguments(constant.type));
     }
     jsAst.New instantiation = new jsAst.New(constructor, fields);
-    return maybeAddTypeArguments(constant.type, instantiation);
+    return instantiation;

[Siggi Cherem (dart-lang), 2016/09/16 18:39:02]

to clarify: is this because the type-information is already passed into the
constructor, so we were practically setting it twice?

[sra1, 2016/09/16 20:09:08]

Exactly. Line 315.

   }
 
   String stripComments(String rawJavaScript) {
     return rawJavaScript.replaceAll(COMMENT_RE, '');
   }
 
   jsAst.Expression maybeAddTypeArguments(
       InterfaceType type, jsAst.Expression value) {
     if (type is InterfaceType &&
         !type.treatAsRaw &&
@@ skipping 20 matching lines @@
       arguments.add(rtiEncoder.getTypeRepresentation(argument, unexpected));
     }
     return new jsAst.ArrayInitializer(arguments);
   }
 
   @override
   jsAst.Expression visitDeferred(DeferredConstantValue constant, [_]) {
     return constantReferenceGenerator(constant.referenced);
   }
 }