Copy stable/9 to releng/9.3 as part of the 9.3-RELEASE cycle.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

Copy head to stable/9 as part of 9.0-RELEASE release cycle.

Approved by: re (implicit)

/* -> /*- for license, minor formatting changes

Include machine/asmacros.h instead of machine/asm.h.

Submitted by: bde

Fixed SBUS_RA_*_region_* functions.

Rewrite the pc98 bus_space stuff.

The type of bus_space_tag_t is now a pointer to bus_space_tag structure,
and the bus_space_tag structure saves pointers to functions for direct
access and relocate access.

Added bsh_bam member to the bus_space_handle structure, it saves access
method either direct access or relocate access which is called by
bus_space_* functions.

Added the mecia device support. If the bs_da and bs_ra in bus tag are set
NEPC_io_space_tag and NEPC_mem_space_tag respectively, new bus_space stuff
changes the register of mecia automatically for 16bit access.

Obtained from: NetBSD/pc98