MFC r330806-r330815, r330837, r330864, r330883

pc98 changes associated with the named commits are also included in this
commit, despite not having been made with the original commits due to its
removal in head.

r330806:
Minor cosmetic changes.

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.

r330807:
We can't use d_opendata for blkio storage.

open_disk uses d_opendata for it's own purpse. We can't store blkio
there. Fortunately, blkio is stored elsewhere and we never actually
retrieve blkio from d_opendata. Eliminate it as a source of confusion.
Eliminate all stores of d_opendata in efi since this layer doesn't own
that field.

r330808:
Make struct libi386_devdesc match the struct devdesc better

Move data to top and call it d_opendata.

r330809:
Use the actual struct devdesc at the start of all *_devdesc structs

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.

r330810:
Remove d_type from devdesc. It's not needed as we can fetch it from
d_dev->dv_type when we need it.

r330811:
GC unused routines.

Sponsored by: Netflix

r330812:
Use the one-line-per-file pattern here, and sort the file names.

Sponsored by: Netflix

r330813:
Move the env convenience routines out of boot1.c.

These routines are more generally useful. Even though boot1 is on its
way out, it's better to make these common during the transition than
copy them.

r330814:
Star BootCurrent entry when booting.

Sponsored by: Netflix

r330815:
Print the load and device path as well as BootCurrent and BootOrder

Sponsored by: Netflix

r330837:
biosdisk.c should not set d_opendata.

Same as 330807, d_opendata is owned by open_disk and we should not
set it.

M stand/i386/libi386/biosdisk.c

r330864:
Prefer uintXX_t to u_intXX_t

A foolish consistency is the hobgoblin of little minds, adored by
little statesmen and philosophers and divines. With consistency a
great soul has simply nothing to do. -- Ralph Waldo Emerson

r330883:
Fix typo that misteriously passes compilation.