(mark_char_byte_table): New function in UTF-2000.

(mark_char_byte_table): New function in UTF-2000.
(char_byte_table_equal): New function in UTF-2000.
(char_byte_table_hash): New function in UTF-2000.
(char_byte_table_description): New constant in UTF-2000.
(char_byte_table): New type in UTF-2000.
(make_char_byte_table): New function in UTF-2000.
(copy_char_byte_table): New function in UTF-2000.
(make_char_code_table): New macro in UTF-2000.
(get_char_code_table): New function in UTF-2000.
(put_char_code_table): New function in UTF-2000.
(mark_charset): Mark `cs->encoding_table' in UTF-2000.
(charset_description): Add setting in UTF-2000.
(make_charset): Setup `CHARSET_ENCODING_TABLE(cs)' instead of
`CHARSET_TO_BYTE1_TABLE(cs)'.
(charset_get_byte1): Refer `XCHARSET_ENCODING_TABLE(charset)' instead
of `XCHARSET_TO_BYTE1_TABLE(charset)'.
(charset_get_byte2): Refer `XCHARSET_ENCODING_TABLE(charset)' instead
of `XCHARSET_TO_BYTE2_TABLE(charset)'.
(Fset_charset_mapping_table): Setup `CHARSET_ENCODING_TABLE(cs)' instead of
`CHARSET_TO_BYTE1_TABLE(cs)' and `CHARSET_TO_BYTE2_TABLE(cs)'.