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

pkg/compiler/lib/src/types/types.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.
 
 library types;
 
 import '../dart2jslib.dart' hide Selector, TypedSelector;
 import '../elements/elements.dart';
 import '../inferrer/type_graph_inferrer.dart' show TypeGraphInferrer;
 import '../tree/tree.dart';
@@ skipping 316 matching lines @@
       TypeMask guaranteedType =
           typesInferrer.getTypeOfSelector(selector);
       return (concreteTypesInferrer == null)
           ? guaranteedType
           : intersection(guaranteedType,
                          concreteTypesInferrer.getTypeOfSelector(selector),
                          selector);
     });
   }
 }