VA blocks are currently stored in an inconsistent way. Sometimes block
end is inclusive, sometimes exclusive. This leads to wrong size
calculations in certain cases, plus could lead to a segmentation fault
in case mapping process fails in the middle and we try to roll it back.
Need to make this consistent - start inclusive till end inclusive.
For example, the regions table may now look like this:
0x0000 - 0x1fff : allocated
0x2000 - 0x2fff : free
0x3000 - 0x3fff : allocated