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

pkg/compiler/lib/src/mirrors_used.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.
 
 library dart2js.mirrors_used;
 
 import 'constants/expressions.dart';
 import 'constants/values.dart' show
     ConstantValue,
     ConstructedConstantValue,
@@ skipping 575 matching lines @@
       // @MirrorsUsed(targets: fisk)
       //                       ^^^^
       //
       // Instead of saying 'fisk' should pretty print the problematic constant
       // value.
       return spannable;
     }
     return node;
   }
 }