* module.c (pointer_info): Make true_name and module pointers
rather than arrays, order pointers before other fields.
(free_pi_tree): free true_name and module as well.
(mio_read_string): Rename to read_string.
(mio_write_string): Remove.
(load_commons): Use read_string.
(read_module): Use read_string rather than mio_internal_string.
(write_blank_common): Call write_atom directly.
(write_symbol): Likewise.