[wwwdocs] Document stack checking improvements for Ada

[Eric Botcazou]

> Excellent, and thanks for taking the time to document this, too.  It
> is clear to me, reading the above, thta this is a compile-time check;
> if you'd like to make this more clear even, you could say something
> like "a compile-time warning should be issued for these cases".  Or
> be more brave and say "will be issued". ;-) 

OK, let's be brave. :-)

-- 
Eric Botcazou