dumpfile format. Without the patch, there is a limitation caused
by several 32-bit members of dump_header structure, in particular
the max_mapnr member, which overflows if the dumpfile contains more
than 16TB of physical memory space. The header_version member of
the dump_header structure has been increased from 0 to 1 in this
extended new format, and the new 64-bit members will be used.
(d.hatayama@jp.fujitsu.com)
