(Vchar_unified_charset_table): Delete it.

(Vchar_unified_charset_table): Delete it.
(inhibit_load_charset_map): New variable.
(temp_charset_work): New variable.
(SET_TEMP_CHARSET_WORK_ENCODER, GET_TEMP_CHARSET_WORK_ENCODER)
(SET_TEMP_CHARSET_WORK_DECODER, GET_TEMP_CHARSET_WORK_DECODER):
New macros.
(load_charset_map): Meaning of control_flag changed.  If
inhibit_load_charset_map is nonzero, setup a table in
temp_charset_work.
(load_charset): New argument control_flag.
(map_charset_for_dump): New function.
(map_charset_chars): If inhibit_load_charset_map is nonzero, use
map_charset_for_dump.
(Fdefine_charset_internal): If the charset method is MAP, load
mapping tables by calling load_charset.
(Funify_charset): Don't load a mapping table but directly set
Vchar_unify_table.
(maybe_unify_char): New function.
(decode_char): Don't handle the deleted method MAP_DEFERRED.
Handle the case of inhibit_load_charset_map being nonzero.
(encode_char): Don't handle the deleted method MAP_DEFERRED.
Handle the case of inhibit_load_charset_map being nonzero.
(Fclear_charset_maps): Just free temp_charset_work.
(syms_of_charset): Make `inhibit-load-charset-map' a Lisp
variable.