Remove library tags, they aren't needed

lib/src/codegen/js_field_storage.dart

Index: lib/src/codegen/js_field_storage.dart
diff --git a/lib/src/codegen/js_field_storage.dart b/lib/src/codegen/js_field_storage.dart
index 773a54b152a7c1777bb7204127dc1be4fb96ddfa..ffb6b770abc04250a743752b4785e16bd5e41a9c 100644
--- a/lib/src/codegen/js_field_storage.dart
+++ b/lib/src/codegen/js_field_storage.dart
@@ -2,8 +2,6 @@
 // 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 dev_compiler.src.codegen.js_field_storage;
-
 import 'dart:collection' show HashMap, HashSet;
 import 'package:analyzer/src/generated/ast.dart' show Identifier;
 import 'package:analyzer/src/generated/element.dart';