Delete dart_backend from compiler.

tests/compiler/dart2js/backend_dart/end2end_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.
-
-/// End-to-end test of the dart2dart compiler.
-library dart_backend.end2end_test;
-
-import 'package:async_helper/async_helper.dart';
-import 'package:compiler/src/compiler.dart';
-import 'package:compiler/src/dart_backend/dart_backend.dart';
-import 'package:expect/expect.dart';
-
-import '../../../../pkg/analyzer2dart/test/test_helper.dart' hide TestSpec;
-import '../../../../pkg/analyzer2dart/test/end2end_data.dart';
-
-import 'test_helper.dart';
-import '../output_collector.dart';
-
-main(List<String> args) {
-  performTests(TEST_DATA, asyncTester, runTest, args);
-}
-
-runTest(TestSpec result) {
-  OutputCollector outputCollector = new OutputCollector();
-  asyncTest(() => compilerFor(result.input, outputProvider: outputCollector)
-      .then((Compiler compiler) {
-    String expectedOutput = result.output.trim();
-    compiler.phase = Compiler.PHASE_COMPILING;
-    DartBackend backend = compiler.backend;
-    backend.assembleProgram();
-    String output = outputCollector.getOutput('', 'dart').trim();
-    Expect.equals(expectedOutput, output,
-        '\nInput:\n${result.input}\n'
-        'Expected:\n$expectedOutput\n'
-        'Actual:\n$output\n');
-  }));
-}