355bcba766
as an argument a function that will retrieve an element of the pointer
arrays in user space. This allows COMPAT_NETBSD32 to share the code for
the emulated version of execve(2), and fixes various issues that came from
the slow drift between the two implementations.
Note: when splitting up a syscall function, I'll use two different ways
of naming the resulting helper function. If it stills does
copyin/out operations, it will be named <syscall>1(). If it does
not (as it was the case for get/setitimer), it will be named
do<syscall>.