(map_over_uint8_byte_table): Cancel temporary hack.

(map_over_uint8_byte_table): Cancel temporary hack.
(map_over_uint16_byte_table): Likewise.
(map_over_byte_table): Likewise.
(get_char_id_table): Refer `cit->default_value'.
(put_char_id_table): Support `CHARTAB_RANGE_DEFAULT'.
(map_char_id_table): Use `1 << 30' instead of `1 << 24' as number of
character-id ranges.
(mark_char_table): Mark `ct->default_value'.
(char_table_description): Add `default_value'.
(fill_char_table): Use `default_value'.
(decode_char_table_range): Decode `nil' as `CHARTAB_RANGE_DEFAULT'.
(get_char_id_table): Refer `cit->default_value'.
(put_char_id_table): Support `CHARTAB_RANGE_DEFAULT'.
(map_char_table): Support `CHARTAB_RANGE_DEFAULT'; cancel temporary
hack; check value of char-table is bound or not.
(slow_map_char_table_fun): Support `CHARTAB_RANGE_DEFAULT'.