The member function "void (*if_watchdog)(struct ifnet *ifp)" was removed in FreeBSD9 (function is deprecated since Nov. 2009)
See discussion: http://lists.freebsd.org/pipermail/freebsd-net/2009-November/023677.html
Since this function was never really used in the vmxnet driver for FreeBSD remove the code with the great site effect compat6 is no longer used to run vmware-tools.
Same goes for the official tools.
patch against vmxnet
Thanks, I bounced this request to our networking guys.