it looks to me that, if __HAVE_MINIMAL_EMUL is defined,
	we can't perform bound checks on syscall number.  am i correct?
	if so, does it make sense to move e_nsysent out of #ifndef
	__HAVE_MINIMAL_EMUL?  it is needed for systrace and such.
	(some of sys/compat/*/*exec.c, such as sunos, does not have #ifndef
	clause, so it can't be compiled with __HAVE_MINIMAL_EMUL defined)

itojun