hammer2 - Add debug ioctl

* Add a a debugging command to dump the in-memory chain topology.
hammer2 - multi-target mount part 4/many (stabilization)

* Fix spmp mirror_tid synchronization bug in the flush code.  TIDs were
  not being allocated properly for the super-root portion of the flush.

* Add in-memory chain dump ioctl.

* Fix another missing modsync.
Revert "Remove crunchgen(8)."

This reverts commit 97c14704c37c914dbd89b22465a421ffde7fe89d.

Conflicts:
	Makefile.inc1
	Makefile_upgrade.inc
	sbin/ifconfig/Makefile
	usr.bin/vi/Makefile
	usr.sbin/ppp/bundle.c
	usr.sbin/pppd/Makefile
	usr.sbin/tcpdump/Makefile
Update crunched binaries tools from FreeBSD

* Fix amd64/x86_64 confusion

* Remove a.out support