Resynthesize enum fields lazily.

pkg/analyzer/test/src/summary/resynthesize_test.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 test.src.serialization.elements_test;
 
 import 'dart:convert';
 
 import 'package:analyzer/dart/ast/ast.dart';
 import 'package:analyzer/dart/constant/value.dart';
@@ skipping 653 matching lines @@
       return;
     }
     expect(original, isNotNull);
     expect(resynthesized, isNotNull, reason: desc);
     if (rImpl is DefaultParameterElementImpl && oImpl is ParameterElementImpl) {
       // This is ok provided the resynthesized parameter element doesn't have
       // any evaluation result.
       expect(rImpl.evaluationResult, isNull);
     } else {
       Type rRuntimeType;
-      if (rImpl is FunctionElementImpl) {
+      if (rImpl is ConstFieldElementImpl) {
+        rRuntimeType = ConstFieldElementImpl;
+      } else if (rImpl is FunctionElementImpl) {
         rRuntimeType = FunctionElementImpl;
       } else {
         rRuntimeType = rImpl.runtimeType;
       }
       expect(rRuntimeType, oImpl.runtimeType);
     }
     expect(resynthesized.kind, original.kind);
     expect(resynthesized.location, original.location, reason: desc);
     expect(resynthesized.name, original.name);
     expect(resynthesized.nameOffset, original.nameOffset, reason: desc);
@@ skipping 3932 matching lines @@
       fail('Unexpectedly tried to get unlinked summary for $uri');
     }
     return serializedUnit;
   }
 
   @override
   bool hasLibrarySummary(String uri) {
     return true;
   }
 }