tv_usec has "long" type for all architecture in FreeBSD
and follows __LP64__. However, this is not true for tv_sec
that has "time_t" type.
Since r320347 that changed time_t from 32 to 64 bit integer
for 32 bit version of powerpc architecture, we have only single
i386 architecture having 32 bit time_t type.
Submitted by: jhb
MFC after: 1 week.