Add ElementKind for factory constructors.

pkg/compiler/lib/src/resolution/members.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 dart2js.resolution.members;
 
 import '../common.dart';
 import '../common/names.dart' show
     Selectors;
 import '../compiler.dart' show
@@ skipping 3740 matching lines @@
       reporter.reportErrorMessage(
           modifierNode, MessageKind.EXTRANEOUS_MODIFIER,
           {'modifier': modifier});
     }
     if (modifiers.isFinal && (modifiers.isConst || modifiers.isVar)) {
       reportExtraModifier('final');
     }
     if (modifiers.isVar && (modifiers.isConst || node.type != null)) {
       reportExtraModifier('var');
     }
-    if (enclosingElement.isFunction) {
+    if (enclosingElement.isFunction || enclosingElement.isConstructor) {
       if (modifiers.isAbstract) {
         reportExtraModifier('abstract');
       }
       if (modifiers.isStatic) {
         reportExtraModifier('static');
       }
     }
     if (node.metadata != null) {
       variables.metadataInternal =
           compiler.resolver.resolveMetadata(enclosingElement, node);
@@ skipping 910 matching lines @@
     }
     return const NoneResult();
   }
 }
 
 /// Looks up [name] in [scope] and unwraps the result.
 Element lookupInScope(DiagnosticReporter reporter, Node node,
                       Scope scope, String name) {
   return Elements.unwrap(scope.lookup(name), reporter, node);
 }