Implement 'analysis.occurrences' for the new analysis driver.

pkg/analysis_server/test/integration/analysis/occurrences_test.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.
 
 import 'package:analysis_server/plugin/protocol/protocol.dart';
 import 'package:test/test.dart';
 import 'package:test_reflective_loader/test_reflective_loader.dart';
 
 import '../integration_tests.dart';
 
@@ skipping 55 matching lines @@
   }
 }
 
 @reflectiveTest
 class OccurrencesTest extends AbstractOccurrencesTest {}
 
 @reflectiveTest
 class OccurrencesTest_Driver extends AbstractOccurrencesTest {
   @override
   bool get enableNewAnalysisDriver => true;
-
-  @failingTest
-  test_occurrences() {
-    //  NoSuchMethodError: The getter 'iterator' was called on null.
-    return super.test_occurrences();
-  }
 }