Revert "Move dart2js from sdk/lib/_internal/compiler to pkg/compiler"

tests/compiler/dart2js/dump_info_test.dart

 // 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.
 // Test that parameters keep their names in the output.
 
 import "package:expect/expect.dart";
 import "package:async_helper/async_helper.dart";
 import 'memory_compiler.dart';
-import 'package:compiler/src/dump_info.dart';
+import 'package:compiler/implementation/dump_info.dart';
 import 'dart:convert';
 
 const String TEST_BASIC= r"""
 library main;
 
 int a = 2;
 
 class c {
   final int m;
   c(this.m) {
@@ skipping 155 matching lines @@
     Expect.isTrue(main_ != null);
     Expect.isTrue(fn1 != null);
     Expect.isTrue(fn2 != null);
     Expect.isTrue(deps.containsKey(main_['id']));
     Expect.isTrue(deps.containsKey(fn1['id']));
     Expect.isTrue(deps.containsKey(fn2['id']));
     Expect.isTrue(deps[main_['id']].any((dep) => dep['id'] == fn1['id']));
     Expect.isTrue(deps[fn1['id']].any((dep) => dep['id'] == fn2['id']));
   });
 }