13728 build zdb command as 64-bit binary
Reviewed by: Yuri Pankov <yuripv@yuripv.dev>
Reviewed by: Andy Fiddaman <Andy@omnios.org>
Approved by: Dan McDonald <danmcd@joyent.com>

PSARC 2002/240 ZFS
6338653 Integrate ZFS
PSARC 2004/652 - DKIOCFLUSH
5096886 Write caching disks need mechanism to flush cache to physical media