Ensure that a complete library element has constants evaluated (issue 24890)

pkg/analysis_server/lib/src/services/completion/dart/completion_manager.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 services.completion.dart.manager;
 
 import 'dart:async';
 
 import 'package:analysis_server/plugin/protocol/protocol.dart';
 import 'package:analysis_server/src/provisional/completion/completion_core.dart'
@@ skipping 128 matching lines @@
         return elem.library;
       }
     }
     return null;
   }
 
   @override
   InterfaceType get objectType {
     if (_objectType == null) {
       Source coreUri = context.sourceFactory.forUri('dart:core');
-      LibraryElement coreLib = context.getLibraryElement(coreUri);
+      LibraryElement coreLib = context.computeLibraryElement(coreUri);
       _objectType = coreLib.getType('Object').type;
     }
     return _objectType;
   }
 
   @override
   Future<List<Directive>> resolveDirectives() async {
     CompilationUnit libUnit;
     if (librarySource == source) {
       libUnit = target.unit;
@@ skipping 63 matching lines @@
         dotTarget = node.realTarget;
       }
     }
     if (node is PrefixedIdentifier) {
       if (identical(node.identifier, target.entity)) {
         dotTarget = node.prefix;
       }
     }
   }
 }