bug#24012: 25.0.95; forward-comment backwards takes O(n^2)

[Eli Zaretskii]

> From:  Leo Liu <sdl.web@gmail.com>
> Cc: 24012@debbugs.gnu.org
> Date: Mon, 18 Jul 2016 08:15:44 +0800
> 
> On 2016-07-17 15:12 +0300, Eli Zaretskii wrote:
> > Because search functions cannot really search backwards?
> 
> But by changing the major mode to octave-mode you get a 12 times speedup
> without doing anything.

Profile it.  One guess is that the different comment syntax somehow
causes this.  But that's a guess.