MF12 r365662:

MFC r365371:

Turn MALLOC_PRODUCTION into a regular src.conf(5) option

For historical reasons, defining MALLOC_PRODUCTION in /etc/make.conf has
been used to turn off potentially expensive debug checks and statistics
gathering in the implementation of malloc(3).

It seems more consistent to turn this into a regular src.conf(5) option,
e.g. WITH_MALLOC_PRODUCTION / WITHOUT_MALLOC_PRODUCTION. This can then
be toggled similar to any other source build option, and turned on or
off by default for e.g. stable branches.

Reviewed by: imp, manpages
Differential Revision: https://reviews.freebsd.org/D26337

MFC r365373:

Follow-up r365371 by removing sentences which indicate the state of the
MK_MALLOC_PRODUCTION option on -CURRENT.

Also, for the sake of backwards compatibility, support the old way of
enabling 'production malloc', e.g. by adding a define in make.conf(5).

MF12 r365671:

Follow-up r365662 (MFC of r365371 and r365373) by correctly setting
WITH_MALLOC_PRODUCTION for stable branches. Also add a note to UPDATING,
to inform users about the new setting.

Direct commit to stable/{11,12} as this does not apply to head.

Noticed by: imp, Ronald Klop <ronald-lists@klop.ws>

MF12 r365672:

Follow-up r365662 (MFC of r365371 and r365373) by also removing the
header hack from jemalloc_FreeBSD.h, which rendered any make.conf
MALLOC_PRODUCTION or src.conf WITH/WITHOUT_MALLOC_PRODUCTION irrelevant.

Direct commit to stable/{11,12} as this does not apply to head.

Noticed by: kevans

Approved by: re (gjb)