"BUS_SPACE_ALIGNED_POINTER()".
Equal to the param.h "ALIGNED_POINTER()" normally, but obeys additional
requirements of the bus_space_xxx_n() macros. (BUS_SPACE_DEBUG)
bus_space(9), if drivers want it (they shouldn't; easy to convert) they
can define it right before including bus.h. There's been a release since
the interfaces were (slightly) changed, and no code in the source tree
uses the old interfaces as far as I can tell.