r330809 replaced duplication of devdesc struct fields with an embedded copy
of the devdesc struct, to avoid fragility. That means all the scattered
comments indicating that structs must match are no longer valid. Likewise
asserts that attempted to mitigate some of the old fragility.
Reviewed by: imp@
The current system is fragile and requires very careful layout of all
*_devdesc structures. It also makes it hard to change the base
devdesc. Take a page from CAM and put the 'header' in all the derived
classes and adjust the code to match.
For OFW, move the iHandle h_handle out of a slot conflicting with
d_opendata. Due to quirks in the alignment rules, this worked.
However changing the code to use d_opendata storage now that it's a
pointer is hard, so just have a separate field for it.
All other cleanups were to make the *_devdesc structures match where
they'd taken some liberties that were none-the-less compatible enough
to work.
Make sure { on the same line as struct for all struct *devdesc. Move
some type definitions to next to the dv_type define, since that's what
sets the d_type.
