bug#59738: c-ts-mode is slow with large buffers.

[Eli Zaretskii]

> From: Yuan Fu <casouri@gmail.com>
> Date: Sat, 10 Dec 2022 15:14:27 -0800
> Cc: Eli Zaretskii <eliz@gnu.org>,
>  59738@debbugs.gnu.org
> 
> Querying time (thus fontification time) increases as the buffer size 
> increases, even if we limit the range of the query to a fixed region (which 
> is what we do in tree-sitter font-lock). This is unlike c-mode, where 
> fontifying a region takes the same amount of time regardless of the buffer 
> size.

The last sentence is inaccurate: sometimes CC Mode must look far
beyond the fixed region which jit-lock.el asks it to fontify.  AFAIR,
that is mainly to figure out the syntactical context of the portion of
the buffer that needs to be fontified.