Delete dart_backend from compiler.

pkg/compiler/lib/src/dart_backend/dart_backend.dart

Index: pkg/compiler/lib/src/dart_backend/dart_backend.dart
diff --git a/pkg/compiler/lib/src/dart_backend/dart_backend.dart b/pkg/compiler/lib/src/dart_backend/dart_backend.dart
deleted file mode 100644
index 729091fd1c995d03b2598779b35bf28635de26e1..0000000000000000000000000000000000000000
--- a/pkg/compiler/lib/src/dart_backend/dart_backend.dart
+++ /dev/null
@@ -1,40 +0,0 @@
-// Copyright (c) 2012, 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 dart_backend;
-
-import 'dart:async' show Future;
-import 'dart:math' show max;
-
-import '../../compiler.dart' show CompilerOutputProvider;
-import '../common.dart';
-import '../common/backend_api.dart' show Backend, ImpactTransformer;
-import '../common/codegen.dart' show CodegenWorkItem;
-import '../common/names.dart' show Selectors, Uris;
-import '../common/registry.dart' show Registry;
-import '../common/resolution.dart' show Resolution, ResolutionImpact;
-import '../common/tasks.dart' show CompilerTask;
-import '../compiler.dart' show Compiler;
-import '../compile_time_constants.dart';
-import '../constants/constant_system.dart';
-import '../constants/expressions.dart';
-import '../constants/values.dart';
-import '../dart_types.dart';
-import '../elements/elements.dart';
-import '../enqueue.dart' show Enqueuer, ResolutionEnqueuer;
-import '../library_loader.dart' show LoadedLibraries;
-import '../mirror_renamer/mirror_renamer.dart';
-import '../resolution/tree_elements.dart' show TreeElements, TreeElementMapping;
-import '../tokens/keyword.dart' show Keyword;
-import '../tree/tree.dart';
-import '../universe/selector.dart' show Selector;
-import '../universe/use.dart' show DynamicUse, TypeUse, TypeUseKind;
-import '../universe/world_impact.dart' show WorldImpact, TransformedWorldImpact;
-import '../util/util.dart';
-import 'backend_ast_to_frontend_ast.dart' as backend2frontend;
-
-part 'backend.dart';
-part 'renamer.dart';
-part 'placeholder_collector.dart';
-part 'outputter.dart';