Reallocate syscall numbers for aio_writev and aio_readv

[asomers]

Summary

Reallocate syscall numbers for aio_writev and aio_readv

The originally chosen numbers interfere with downstream projects'
syscalls. Move them to the end of the syscall table instead.

Reported by: jrtc27

Regenerate syscall files after reallocation of aio_writev/aio_readv

Test Plan

existing aio test suite

[asomers]

@jrtc27 @brooks the FreeBSD 13 KBI freeze is tomorrow. If you want these syscall numbers to get changed, please review ASAP!

[brooks]

Thank you!

[asomers]

Fixed by https://cgit.freebsd.org/src/commit/?id=b3286afae364c065183da3a910a33db3032529d4 .