(ADJUST_CHAR_POS): New macro.

(ADJUST_CHAR_POS): New macro.
(combine_bytes): Use the macro ADJUST_CHAR_POS.
(adjust_after_replace): New arg REPLACE.  If it is zero, give LEN
as the arg LENGTH to offset_intervals.
(del_range_2): Give correct args to count_combining_before and
combine_bytes.  Adjust the gap position after record_delete if
necessary.  Give character position to adjust_overlays_for_delete.