make stuff compile on openbsd again

make stuff compile on openbsd again
clean up a few other things while we're here.

base/bitfield.hh:
base/compression/null_compression.hh:
    dont #include <inttypes.hh> use "sim/host.hh"
    fix #include guard
base/stats/types.hh:
    dont #include <inttypes.hh> use "sim/host.hh"
kern/linux/aligned.hh:
    dont #include <stdint.hh> use "sim/host.hh"
    fix #include guard
kern/linux/hwrpb.hh:
    fix #include guard

--HG--
extra : convert_revision : 288c687a59a1e770bbb834879173e1a2ea371bce