Use fields in hidden native DOM classes instead of getters/setters.

client/dom/generated/src/frog/HTMLUListElement.dart

 
 class _HTMLUListElementJs extends _HTMLElementJs implements HTMLUListElement native "*HTMLUListElement" {
 
-  bool get compact() native "return this.compact;";
+  bool compact;
 
-  void set compact(bool value) native "this.compact = value;";
-
-  String get type() native "return this.type;";
-
-  void set type(String value) native "this.type = value;";
+  String type;
 }