Refactor one more use of serializeUnlinkedReference

pkg/analyzer/lib/src/summary/summarize_elements.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.
 
 library serialization.elements;
 
 import 'package:analyzer/dart/element/element.dart';
 import 'package:analyzer/dart/element/type.dart';
 import 'package:analyzer/src/dart/element/element.dart';
 import 'package:analyzer/src/dart/element/member.dart';
@@ skipping 535 matching lines @@
         if (executableElement.isFactory) {
           InterfaceType returnType = redirectedConstructor is ConstructorMember
               ? redirectedConstructor.definingType
               : redirectedConstructor.enclosingElement.type;
           EntityRefBuilder typeRef =
               serializeTypeRef(returnType, executableElement);
           if (redirectedConstructor.name.isNotEmpty) {
             String name = redirectedConstructor.name;
             int typeId = typeRef.reference;
             LinkedReference typeLinkedRef = linkedReferences[typeId];
-            unlinkedReferences.add(new UnlinkedReferenceBuilder(
-                name: name, prefixReference: typeId));
-            int refId = linkedReferences.length;
-            linkedReferences.add(new LinkedReferenceBuilder(
-                kind: ReferenceKind.constructor, unit: typeLinkedRef.unit));
+            int refId = serializeUnlinkedReference(
+                name, ReferenceKind.constructor,
+                unit: typeLinkedRef.unit, prefixReference: typeId);
             b.redirectedConstructor = new EntityRefBuilder(
                 reference: refId, typeArguments: typeRef.typeArguments);
           } else {
             b.redirectedConstructor = typeRef;
           }
         } else {
           b.redirectedConstructorName = redirectedConstructor.name;
         }
       }
       if (executableElement.isConst &&
@@ skipping 712 matching lines @@
       exportNames.add(new LinkedExportNameBuilder(
           name: name,
           dependency: serializeDependency(dependentLibrary),
           unit: unit,
           kind: kind));
     }
     pb.exportNames = exportNames;
     return pb;
   }
 }