Delay finishing dart:core and dart:async libraries until after TypeProvider is set for the context.

pkg/analyzer/lib/src/dart/analysis/library_analyzer.dart

 // Copyright (c) 2017, 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.
 
 import 'package:analyzer/context/declared_variables.dart';
 import 'package:analyzer/dart/ast/ast.dart';
 import 'package:analyzer/dart/ast/visitor.dart';
 import 'package:analyzer/dart/element/element.dart';
 import 'package:analyzer/error/error.dart';
 import 'package:analyzer/error/listener.dart';
@@ skipping 68 matching lines @@
       _resolveUriBasedDirectives(file, unit);
     });
 
     _createAnalysisContext();
 
     try {
       _resynthesizer = new StoreBasedSummaryResynthesizer(
           _context, _sourceFactory, _analysisOptions.strongMode, _store);
       _typeProvider = _resynthesizer.typeProvider;
       _context.typeProvider = _typeProvider;
+      _resynthesizer.finishCoreAsyncLibraries();
 
       _libraryElement = _resynthesizer.getLibraryElement(_library.uriStr);
 
       _resolveDirectives(units);
 
       units.forEach((file, unit) {
         _resolveFile(file, unit);
         _computePendingMissingRequiredParameters(file, unit);
       });
 
@@ skipping 700 matching lines @@
 }
 
 /**
  * Either the name or the source associated with a part-of directive.
  */
 class _NameOrSource {
   final String name;
   final Source source;
   _NameOrSource(this.name, this.source);
 }