allows this tool to compile again. Albeit, now to test a new malloc
implementation one has to install the new libc which may have bad
consequences (i.e. if the new malloc implementation were buggy).
Add logic to workaround malloc's current behaviour of returning an
invalid non-NULL pointer for 0 byte allocation requests; this prevents the
tool from coring during the NOPS loop.
Add $FreeBSD$ tags.
