Fix for adding new elements into library cycles.

pkg/analyzer/lib/src/dart/element/element.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 analyzer.src.dart.element.element;
 
 import 'dart:collection';
 import 'dart:math' show min;
 
 import 'package:analyzer/dart/ast/ast.dart';
@@ skipping 5854 matching lines @@
       }
     }
     return null;
   }
 
   /** Given an update to this library which may have added or deleted edges
    * in the import/export graph originating from this node only, remove any
    * cached library cycles in the element model which may have been invalidated.
    */
   void invalidateLibraryCycles() {
-    if (_libraryCycle == null) {
-      // We have already invalidated this node, or we have never computed
-      // library cycle information for it.  In the former case, we're done. In
-      // the latter case, this node cannot be reachable from any node for which
-      // we have computed library cycle information.  Therefore, any edges added
-      // or deleted in the update causing this invalidation can only be edges to
-      // nodes which either have no library cycle information (and hence do not
-      // need invalidation), or which do not reach this node by any path.
-      // In either case, no further invalidation is needed.
-      return;
-    }
     // If we have pre-computed library cycle information, then we must
     // invalidate the information both on this element, and on certain
     // other elements.  Edges originating at this node may have been
     // added or deleted.  A deleted edge that points outside of this cycle
     // cannot change the cycle information for anything outside of this cycle,
     // and so it is sufficient to delete the cached library information on this
     // cycle.  An added edge which points to another node within the cycle
     // only invalidates the cycle.  An added edge which points to a node earlier
     // in the topological sort of cycles induces no invalidation (since there
     // are by definition no back edges from earlier cycles in the topological
@@ skipping 2590 matching lines @@
 
   @override
   void visitElement(Element element) {
     int offset = element.nameOffset;
     if (offset != -1) {
       map[offset] = element;
     }
     super.visitElement(element);
   }
 }