Suggestion: Move xparse.el to latex.el

[Gustavo Barros]

Hi All,

I've notice the latest release included some improvements to `xparse.el' 
(commit 9b223d0641f3c11d48ca974ace9b5d70719814df) which, of course, is 
welcome.

But since the LaTeX release of 2020/10/01, `xparse' is part of the 
kernel as `ltcmd.dtx', and `\NewDocumentCommand' and friends are 
actually available out of the box, with no need to load `xparse' 
explicitly anymore.

I guess the same is true of the symbols `\ExplSyntaxOn' and 
`\ExplSyntaxOff'.  Well, considering the contents of `expl3.el', I'm not 
sure whether the syntax changes made there would be granted by default 
in a regular LaTeX document (probaly not), and all else it does is 
related to package options.  But, the mentioned symbols could be made 
available by default, I think.  Just as `\makeatletter' / `\makeatother' 
are.

What do you think of moving this support to somewhere where it is loaded 
by default (rather than depending on the style file for `xparse')? I 
presume it would be `latex.el', but where it's deemed appropriate.

Best regards,
Gustavo.