(decode_coding_iso2022): Update coding->fake_multibyte.

(decode_coding_iso2022): Update coding->fake_multibyte.
(ENCODE_SINGLE_SHIFT_2, ENCODE_SINGLE_SHIFT_3,
encode_coding_iso2022, decode_coding_sjis_big5,
encode_coding_sjis_big5, decode_eol, encode_eol, decode_coding,
encode_coding): Likewise.
(shrink_decoding_region, shrink_encoding_region): Do not skip
non-ASCII code in any cases.  Bug fix for getting starting address
from BEG.
(code_convert_region): Sync character positions correctly by
paying attention to coding->fake_multibyte.
(code_convert_string): Set number of character and bytes just
processed in members of CODING.
(code_convert_string): Adjusted for the change of
code_convert_region.
(code_convert_region1): Likewise.