(CODING_ISO_CMP_STATUS): New macro.

(CODING_ISO_CMP_STATUS): New macro.
(CODING_ISO_EXTSEGMENT_LEN, CODING_ISO_EMBEDDED_UTF_8): New macros.
(MAX_ANNOTATION_LENGTH): Defined to 5.
(ADD_COMPOSITION_DATA): New arg nbytes.
(emacs_mule_char): New arg cmp_status.
(DECODE_EMACS_MULE_COMPOSITION_CHAR): Delete it.
(DECODE_EMACS_MULE_COMPOSITION_RULE_20): New arg c.
(DECODE_EMACS_MULE_COMPOSITION_RULE_21): New arg c.
(DECODE_EMACS_MULE_21_COMPOSITION): Delete the arg c.
(DECODE_EMACS_MULE_20_RELATIVE_COMPOSITION): Likewise.
(DECODE_EMACS_MULE_20_RULEBASE_COMPOSITION): Likewise.
(DECODE_EMACS_MULE_COMPOSITION_START): New macro.
(EMACS_MULE_COMPOSITION_END): New macro.
(emacs_mule_finish_composition): New function.
(EMACS_MULE_MAYBE_FINISH_COMPOSITION): New macro.
(decode_coding_emacs_mule): Avoid long looking ahead while
handling composition.
(DECODE_COMPOSITION_RULE): Argument changed to rule and nbytes.
(ENCODE_COMPOSITION_RULE): New macro.
(finish_composition): New function.
(MAYBE_FINISH_COMPOSITION): Call finish_composition.
(DECODE_COMPOSITION_START): New implementation.
(DECODE_COMPOSITION_END): Likewise.
(STORE_COMPOSITION_RULE): New macro.
(decode_coding_iso_2022): Avoid long looking ahead while handling
composition, CTEXT extended segment, and embedded UTF-8.
(setup_coding_system): For a coding of type iso-2022, reset
CODING_ISO_EXTSEGMENT_LEN (coding) and
CODING_ISO_EMBEDDED_UTF_8 (coding).
(get_translation): Delete arguments last_block, from_nchars,
to_nchars.  Callers changed.
(produce_chars): Don't modify charbuf.  Adjusted for the change of
get_translation.
(produce_composition): Adjusted for the new annotation sequence.
(handle_composition_annotation): Likewise.
(consume_chars): Adjusted for the change of get_translation.