bug#59641: term is very slow

[Eli Zaretskii]

> From: Akib Azmain Turja <akib@disroot.org>
> Cc: 59641@debbugs.gnu.org
> Date: Sat, 17 Dec 2022 18:32:09 +0600
> 
> I guess the hot spot here is 'vertical-motion'.  'vertical-motion' takes
> various things into account, which are unnecessary for a terminal
> emulator.  Eat implements its own motion functions, which make their own
> assumptions (e.g. each character takes exactly one column, each line
> finishes with a newline, etc).  I guess this might be a reason why Eat
> is faster.

If there's no need for the specific features that vertical-motion
provides, calling it might indeed be unnecessary.