The last byte of balloc.c's block pointer could be changed from 10 or 13 to
0. On amd64, this is not possible. On i386, this is possible and usually
causes a crash soon.
In rare cases, this sharing caused the ircd to skip
part of outgoing traffic, e.g. appearing as "not enough
parameters" errors on the other side.
The purpose of this flag can be fulfilled by the writeofs
in the bufhead.
libratbox r25227
