Make type system changes backwards compatible

pkg/analyzer/test/src/task/strong_mode_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.task.strong_mode_test;
 
 import 'package:analyzer/src/generated/ast.dart';
 import 'package:analyzer/src/generated/element.dart';
 import 'package:analyzer/src/generated/source.dart';
 import 'package:analyzer/src/task/dart.dart';
 import 'package:analyzer/src/task/strong_mode.dart';
 import 'package:analyzer/task/dart.dart';
 import 'package:unittest/unittest.dart';
 
 import '../../reflective_tests.dart';
 import '../../utils.dart';
 import '../context/abstract_context.dart';
 
 main() {
   initializeTestEnvironment();
   runReflectiveTests(InstanceMemberInferrerTest);
   runReflectiveTests(VariableGathererTest);
 }
 
 @reflectiveTest
 class InstanceMemberInferrerTest extends AbstractContextTest {
   InstanceMemberInferrer get createInferrer =>
-      new InstanceMemberInferrer(context.typeProvider, context.typeSystem);
+      new InstanceMemberInferrer(context.typeProvider,
+          typeSystem: context.typeSystem);
 
   /**
    * Add a source with the given [content] and return the result of resolving
    * the source.
    */
   CompilationUnitElement resolve(String content) {
     Source source = addSource('/test.dart', content);
     return context.resolveCompilationUnit2(source, source).element;
   }
 
@@ skipping 862 matching lines @@
     }
   }
 }
 ''');
     CompilationUnit unit = context.resolveCompilationUnit2(source, source);
     VariableGatherer gatherer = new VariableGatherer(filter);
     unit.accept(gatherer);
     return gatherer.results;
   }
 }