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

tests/compiler/dart2js/simple_inferrer_callers_test.dart

 // Copyright (c) 2013, 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 computation of callers of an element works when two
 // elements of the same name are being invoked in the same method.
 
 import 'package:expect/expect.dart';
 import "package:async_helper/async_helper.dart";
-import 'package:compiler/implementation/types/types.dart';
-import 'package:compiler/implementation/inferrer/type_graph_inferrer.dart';
+import 'package:compiler/src/types/types.dart';
+import 'package:compiler/src/inferrer/type_graph_inferrer.dart';
 
 import 'compiler_helper.dart';
 import 'parser_helper.dart';
 
 const String TEST = """
 class A {
   var field;
 }
 
 class B {
@@ skipping 22 matching lines @@
     var mainElement = findElement(compiler, 'main');
     var classA = findElement(compiler, 'A');
     var fieldA = classA.lookupLocalMember('field');
     var classB = findElement(compiler, 'B');
     var fieldB = classB.lookupLocalMember('field');
 
     Expect.isTrue(inferrer.getCallersOf(fieldA).contains(mainElement));
     Expect.isTrue(inferrer.getCallersOf(fieldB).contains(mainElement));
   }));
 }