enum checkpoint_opcodes, struct checkpoint_op, and
MAX_SNAPSHOT_VMNAME are not vmm specific.
They are used for the save/restore functionality that bhyve(8) offers
and are better suited in usr.sbin/bhyve/snapshot.h.
Since bhyvectl(8) is a consumer of these variables, the Makefile for bhyvectl(8)
has been modified to include usr.sbin/bhyve/snapshot.h.
bhyve/snapshot.h requires definitions provided by ucl.h, so the bhyvectl(8)
Makefile has been modified to also include libucl. The libucl include dependency
will be removed in a later commit.