The rename logic in process_renames() handles renames and merging of file
contents and then marks files as processed. However, there may be higher
stage entries left in the index for other reasons (e.g., due to D/F
conflicts). By checking for such cases and marking the entry as not
processed, it allows process_entry() later to look at it and handle those
higher stages.
Signed-off-by: Elijah Newren <newren@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>