Previous change fixed the old dumpfile vs. new dumpfile check, but
removed an existing (but flawled) old Zim fpath vs. new Zim fpath check.
We should be doing both checks the right way now.
first because simpler is usually better, and second because we cannot
always guarantee that the .latest_comp file, which was holding the list
of all completion functions, is consistently in sync with the dumpfile
that is generated afterwards.
that removes the dumpfile if it's outdated, so it will get dumped again
when the shell starts next time. We're not using comdump because wrapped
ZLE widgets cannot or should not be identified by compdump when they
have a different name than the original one.
See https://github.com/zsh-users/zsh-syntax-highlighting/issues/851
