bug#73302: TeX-find-closing-brace and verbatim macros

[Paul Nelson]

Hello,

Steps to reproduce:
1. Create a TeX file with a verbatim macro, e.g., \email{foo@bar.com},
or anything in (LaTeX-verbatim-macros-with-braces).
2. Put the cursor on the first character inside the braces.
3. M-: (TeX-find-closing-brace)

This should return position after closing brace, but instead returns nil.

This bug affects the folding of verbatim macros, through a chain of
function calls from TeX-fold-hide-item to TeX-find-closing-brace.

The issue is similar to one addressed by up-list in lisp.el - the key
point is to recover gracefully from the failed call to (scan-lists
(point) 1 1), rather than to give up altogether.  A similar fix might
be possible, but I thought I'd raise the issue here first.

Thanks, best,

Paul