vc isn't necessarily loaded even when vc-hooks (where vc-follow-symlinks
is located) is. Setting this variable in :config seemed to work before,
so I think there must have been a recent change in Emacs.
Unlike the previous version, this doesn't take a stance on a word after
a hyphen. I'm ok with this because this function always requires a
check afterwards and is just meant to take care of the common cases.