extract named constructor suggestions from prefixed element contributor

pkg/analysis_server/lib/src/services/completion/prefixed_element_contributor.dart

 // Copyright (c) 2014, 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 services.completion.contributor.dart.invocation;
 
 import 'dart:async';
 
 import 'package:analysis_server/src/services/completion/dart_completion_manager.dart';
 import 'package:analysis_server/src/services/completion/local_declaration_visitor.dart';
@@ skipping 246 matching lines @@
 
   _PrefixedIdentifierSuggestionBuilder(this.request);
 
   @override
   bool computeFast(AstNode node) {
     return false;
   }
 
   @override
   Future<bool> computeFull(AstNode node) {
-    if (node is ConstructorName) {
-      // some PrefixedIdentifier nodes are transformed into
-      // ConstructorName nodes during the resolution process.
-      return new NamedConstructorSuggestionBuilder(request).computeFull(node);
-    }
     if (node is PrefixedIdentifier) {
       SimpleIdentifier prefix = node.prefix;
       if (prefix != null) {
         Element element = prefix.bestElement;
         DartType type = prefix.bestType;
         if (element is! ClassElement) {
           if (type == null || type.isDynamic) {
             //
             // Given `g. int y = 0;`, the parser interprets `g` as a prefixed
             // identifier with no type.
@@ skipping 79 matching lines @@
     }
     return new Future.value(false);
   }
 
   @override
   Future<bool> visitVariableElement(VariableElement element) {
     InterfaceTypeSuggestionBuilder.suggestionsFor(request, element.type);
     return new Future.value(true);
   }
 }