bug#31852: Make memory-limit obsolete

[Paul Eggert]

Tags: patch

The memory-limit function has an implementation that is a relic of 
long-ago days when the heap was allocated via sbrk. This assumption is 
often no longer true now that ASLR is popular, and once we get portable 
dumping work it'll be true even less often. Since memory-limit returns 
nonsense so often and since nobody cares, we can and should mark 
memory-limit as obsolete. On its way out we can move it to a Lisp 
implementation and cause it to be at least somewhat more plausible.

Proposed patches attached. The first patch moves memory-limit to Lisp, 
the second one marks it obsolete. I didn't know where to put the Lisp 
implementation so I put it into lisp/subr.el.

0001-Rewrite-memory-limit-in-Lisp.patch
Description: Text Data

0002-Obsolete-memory-limit.patch
Description: Text Data