16MB alloc in zdb_embedded_block() can cause cores in certain situations
(clang, gcc55).
OsX commit: ced236a5da
FreeBSD commit: https://svnweb.freebsd.org/base?view=revision&revision=326150
illumos/illumos-gate@03a4c2f4bf
Reviewed by: Igor Kozhukhov <igor@dilos.org>
Reviewed by: Andriy Gapon <avg@FreeBSD.org>
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Approved by: Dan McDonald <danmcd@joyent.com>
Author: Jorgen Lundman <lundman@lundman.net>