bug#22086: 25.1.50; [PATCH] Integrate the musl hybrid mallo

[Wolfgang Jenkner]

On Sat, Jan 30 2016, Paul Eggert wrote:

> I think it's ready enough for the master branch, so I committed it
> there and will mark this bug as done.

Thanks, I think patch 5 of my OP (for turning off direct use of mmap for
buffer allocations on FreeBSD) should also be applied.

When I do this, the build is correctly configured for hybrid malloc on
such a system, but linking temacs now fails with

  CCLD     temacs
gmalloc.o: In function `align':
/usr/opt/src/emacs-paul-test/src/gmalloc.c:440: undefined reference to 
`__after_morecore_hook'
/usr/opt/src/emacs-paul-test/src/gmalloc.c:441: undefined reference to 
`__after_morecore_hook'
gmalloc.o: In function `malloc_initialize_1':
/usr/opt/src/emacs-paul-test/src/gmalloc.c:553: undefined reference to 
`__malloc_initialize_hook'
/usr/opt/src/emacs-paul-test/src/gmalloc.c:554: undefined reference to 
`__malloc_initialize_hook'
collect2: error: ld returned 1 exit status
Makefile:594: recipe for target 'temacs' failed