bug#24892: {s, }brk removed from FreeBSD 11.x and later, arm64 architecture

[Eli Zaretskii]

> Cc: 24892@debbugs.gnu.org
> From: Paul Eggert <eggert@cs.ucla.edu>
> Date: Wed, 9 Nov 2016 00:27:04 -0800
> 
> Eli Zaretskii wrote:
> > would it make sense to provide a different
> > implementation, which will be more useful?
> 
> It might if someone were to write it. It would not be likely to have the same 
> API, though.

I think we could lift the implementation from
system_process_attributes, we report there the process memory size.