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

pkg/compiler/lib/src/inferrer/map_tracer.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.
 
 part of type_graph_inferrer;
 
 Set<String> okMapSelectorsSet = new Set.from(
     const <String>[
       // From Object.
       "==",
@@ skipping 104 matching lines @@
           return;
         }
       }
     } else if (selector.isCall &&
                !info.targets.every((element) => element.isFunction)) {
       bailout('Passed to a closure');
       return;
     }
   }
 }