[m-rev.] for review: reduce memory allocation in lexer.m

[Zoltan Somogyi]

On Tue, 30 Jul 2019 15:39:21 +1000 (AEST), Julien Fischer <jfischer at opturion.com> wrote:
> > When doing "mmc --make-short-interface *.m" in the compiler, this diff
> > reduces the overall amount of memory allocated by almost half, with
> > the amount allocated by the scanner going from 76 Mb to 13.5 Mb.
> 
> Nicely done!

Thanks.

> > +    % A line_context and a line_posn together contain exaxtly the same
> 
> s/exaxtly/exactly/

Fixed, and I added XXXs with your proposals for the future in the relevant places.

Thanks for the review.

Zoltan.