Ast_helper.RfRow fields
val mk : 
  ?loc:loc ->
  ?attrs:attrs ->
  Parsetree.row_field_desc ->
  Parsetree.row_fieldval tag : 
  ?loc:loc ->
  ?attrs:attrs ->
  Asttypes.label with_loc ->
  bool ->
  Parsetree.core_type list ->
  Parsetree.row_fieldval inherit_ : ?loc:loc -> Parsetree.core_type -> Parsetree.row_field