Check the live bytes value of a region against the region bitmap.

When the live bytes count of a region is defined (i.e. different
from -1), check that it matches the number of (allocated) bytes
used by live objects in this region, according to the region
space bitmap.

This check is only enabled in debug mode.

Test: art/test.py
Bug: 74064045
Change-Id: I602f5ac7e6a69d52437628844b970a2db9481857