Front ends:
- aligned_alloc
- calloc
- posix_memalign
Fork hooks:
- _malloc_prefork
- _malloc_postfork
- _malloc_postfork_child
Otherwise these will pull in the jemalloc definitions from libc,
which (a) defeats the purpose, and (b) won't work correctly with
fork and threads.
Thanks to kre@ and the thread on tech-userlevel for pointing me in
the right direction to making this actually work to override
jemalloc:
https://mail-index.netbsd.org/tech-userlevel/2023/06/30/msg013957.html
Note: libbsdmalloc doesn't set errno=ENOMEM on malloc failure, but
these front ends do (even aligned_alloc, which is from C11, which
doesn't define ENOMEM at all, but this pacifies our aligned_alloc
tests in t_posix_memalign.c). Might want to fix that.
XXX pullup-10