bug#24166: With --eval, errors in string-match-p do not produce backtraces (but errors in string-match do?!)

[Eli Zaretskii]

> From: npostavs@users.sourceforge.net
> Date: Fri, 05 Aug 2016 22:15:09 -0400
> Cc: 24166@debbugs.gnu.org
> 
> > Is the following a bug?
> 
> Yes, it's another instance of #23949

Indeed.

> Actually, I wonder why the trivial fix suggested there wasn't applied already:

I think Andreas's suggestion to do this in call_debugger is more
robust, because it does that for _any_ debugger whose value is placed
in the 'debugger' variable, not just for debug.el.

Would you please make that change?

TIA