Re-arrange some variables in kinfo_proc, and add more spare room. This
makes the amount of spare room consistent across architectures, and gets
rid of some cases where space was wasted-and-unusable because types have
different sizes & alignment on different hardware platforms. This change
causes more variables to move around on i386, and is much less disruptive
on other platforms. This has been tested on i386, ppc, and sparc, and has
at least been compiled on everything but arm.

Reviewed by: no objections from freebsd-arch, bde