The mixed little/big-endianness of SMBIOS UUIDs was clarified in v2.6
of the SMBIOS spec. dmidecode uses the reported version of SMBIOS to
determine the layout and what to byte-swap.
bhyve's SMBIOS reported as 2.4 though it implemented the 2.6-style of
memory layout. This resulted in dmidecode reporting a different
UUID than one passed in via the -U option.
Fix by exporting a version of 2.6.
Reviewed by: tychon
Reported by: julian
MFC after: 1 day
Previously the sizes were inferred indirectly based on the size of the mappings
at 0 and 4GB respectively. This works fine as long as size of the allocation is
identical to the size of the mapping in the guest's address space. However, if
the mapping is disjoint then this assumption falls apart (e.g., due to the
legacy BIOS hole between 640KB and 1MB).
