The BSD partition table partitioner extends the PC type partition table
partitioner. Both the partition tables shares the same disk;
the BSD disklabel lies in one of PC type partitions.
The functions read_bsd_partitions and commit_bsd_partitions
are implemented. In addition to PC type partition table disk parameters
there is one disk parameter of interval type identified by
UP_ID_PCnumpars specifying the number of the last true PC type
partition and eight disk parameters of interval type identified
by UP_ID_PCBSDpart(x) (x is a character from a to h)
specifying partitions labelled by a, ..., h in the BSD disklabel.