Rewrite memory-limit in Lisp

Have it return Emacs virtual memory size, not the sbrk value
which is often useless newadays.
* doc/lispref/internals.texi (Garbage Collection):
* etc/NEWS: Document this.
* lisp/subr.el (memory-limit): New implementation in Lisp,
written in terms of process-attributes, and which returns
virtual memory size.
* src/alloc.c (Fmemory_limit): Remove C implementation.

1 files changed, 3 insertions, 0 deletions

diff --git a/etc/NEWS b/etc/NEWS
index cecd3f81f85..d59b4a7cf4f 100644
--- a/etc/NEWS
+++ b/etc/NEWS
@@ -665,6 +665,9 @@ instead of just Microsoft platforms.  This fixes a 'get-free-disk-space'
 bug on OS X 10.8 and later (Bug#28639).
 
 +++
+** 'memory-limit' now returns a better estimate of memory consumption.
+
++++
 ** New macro 'combine-change-calls' arranges to call the change hooks
 ('before-change-functions' and 'after-change-functions') just once
 each around a sequence of lisp forms, given a region.  This is