bug#74110: [PATCH] Add folding support for TeX dashes

[Paul Nelson]

> What about folding for dashes, i.e., this report?  Do we want to get it
> in as well?  If so, I think we have to review the change suggested.

I think we can discard the dashes patch, given that the prettification
option seems to have some advantages when it comes to dashes.  For
instance, prettification behaves well with respect to further folding,
e.g., in \begin{theorem}[Cauchy--Schwarz].  Here "--" remains prettified
if we further fold the theorem environment, but I don't know how to "keep
it folded".