Back out #155, it was problematic on HEAD.  Reapply when it's
reworked and better tested.
Pull up following revision(s) (requested by dholland in ticket #156):
	sys/kern/kern_exec.c: revision 1.409
PR/49287: David Holland: Skip the right number of bytes to go over the first
argument in the argv vector. Fixes netbsd32 script execution, where you lost
the first argument because it skipped 8 bytes instead of 4.
Ticket #156