Possible current breakage

[Masao Uebayashi <uebayasi%tombi.co.jp@localhost>]

As you may see I made a low-level UVM change (sys/uvm/uvm_page.*)
and some kernel header rototills.  I've broken:

- evbarm build (fixed)
- hp700 userland build (patch sent to port-hp700@)
- sparc rump build failed (should be fixed now)
- vax doesn't boot (investigating)

All build breakages are my mistakes.  I'd appreciate any works-for-me
report other than x86, arm, ppc.

Thanks for your patience.

Masao