Another fix incremental constants - annotations should use the old unit element.

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 2515 matching lines @@
 
   /**
    * The element representing the field, variable, or constructor being used as
    * an annotation.
    */
   Element element;
 
   /**
    * The compilation unit in which this annotation appears.
    */
-  final CompilationUnitElementImpl compilationUnit;
+  CompilationUnitElementImpl compilationUnit;
 
   /**
    * The AST of the annotation itself, cloned from the resolved AST for the
    * source code.
    */
   Annotation annotationAst;
 
   /**
    * The result of evaluating this annotation as a compile-time constant
    * expression, or `null` if the compilation unit containing the variable has
@@ skipping 5938 matching lines @@
 
   @override
   void visitElement(Element element) {
     int offset = element.nameOffset;
     if (offset != -1) {
       map[offset] = element;
     }
     super.visitElement(element);
   }
 }