Modifies the specified holder record of the target identifier in
    the rights database.

    Format

      SYS$MOD_HOLDER  id ,holder ,[set_attrib] ,[clr_attrib]

    C Prototype

      int sys$mod_holder  (unsigned int id, struct _generic_64

                          *holder, unsigned int set_attrib, unsigned

                          int clr_attrib);