(struct delayed_set_stat): New member 'after_symlinks'.

(struct delayed_set_stat): New member 'after_symlinks'.
(delay_set_stat): Initialize it to 0.
(set_mode): New arg current_stat_info.  Use it (if nonnull) to avoid
taking an extra stat ourselves.  All callers changed.
(set_stat): Likewise.
(apply_nonancestor_delayed_set_stat): New arg 'after_symlinks'.
If false, stop when encountering a struct whose 'after_symlinks' member is
true.  Otherwise, go through all structures but check them more carefully.
All callers changed.
(extract_archive): When extracting a deferred symlink, if its parent
directory's status needs fixing, then mark the directory as needing
to be fixed after symlinks.
(extract_finish): Fix status of ordinary directories, then apply delayed
symlinks, then fix the status of directories that are ancestors
of delayed symlinks.