Add an analysis option to disable cache flushing.

pkg/analyzer/test/src/context/builder_test.dart

 // Copyright (c) 2016, 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 analyzer.test.src.context.context_builder_test;
 
 import 'package:analyzer/file_system/file_system.dart';
 import 'package:analyzer/file_system/memory_file_system.dart';
 import 'package:analyzer/plugin/options.dart';
 import 'package:analyzer/source/package_map_resolver.dart';
@@ skipping 645 matching lines @@
     expect(actual.incremental, expected.incremental);
     expect(actual.incrementalApi, expected.incrementalApi);
     expect(actual.incrementalValidation, expected.incrementalValidation);
     expect(actual.lint, expected.lint);
     expect(actual.preserveComments, expected.preserveComments);
     expect(actual.strongMode, expected.strongMode);
     expect(actual.strongModeHints, expected.strongModeHints);
     expect(actual.implicitCasts, expected.implicitCasts);
     expect(actual.implicitDynamic, expected.implicitDynamic);
     expect(actual.trackCacheDependencies, expected.trackCacheDependencies);
+    expect(actual.disableCacheFlushing, expected.disableCacheFlushing);
     expect(actual.finerGrainedInvalidation, expected.finerGrainedInvalidation);
   }
 
   Uri _relativeUri(String path, {String from}) {
     String relativePath = pathContext.relative(path, from: from);
     return pathContext.toUri(relativePath);
   }
 }
 
 @reflectiveTest
@@ skipping 35 matching lines @@
       fail('Unexpected invocation of optionsProcessed');
     }
     expect(options, hasLength(expectedOptions.length));
     for (String key in expectedOptions.keys) {
       expect(options.containsKey(key), isTrue, reason: 'missing key $key');
       expect(options[key], expectedOptions[key],
           reason: 'values for key $key do not match');
     }
   }
 }