kern/141235: 8.0 no longer provides /dev entries for all disk slices [regression]

[dieterbsd at engineer.com]

>> and then I added GEOM_MBR and GEOM_BSD as suggested.  So I don't
>> know where GEOM_PART_MBR comes from or how to get rid of it.
>
> GEOM_PART_* are in DEFAULTS (sys/amd64/conf/DEFAULTS on amd64).

Ah ha!

opt_geom.h now contains:

#define GEOM_BSD 1
#define GEOM_LABEL 1
#define GEOM_PART_GPT 1
#define GEOM_MBR 1

(same as 7.1 had)

Now I have /dev entries for extended partitions, and the
duplicate and bogus entries are gone.  GUID partitioning
and partition labels still work.  Yea!

Having some GEOM options in DEFAULTS and some in the config file
seems prone to error.  I suggest putting them all in the same file.
Yes, grep can easily find it, but despite many years of experience
with grep, find, and xargs I somehow managed to miss DEFAULTS.
I can only blame lack of sleep.

Having both GEOM_MBR and GEOM_PART_MBR is confusing.  If there is a
good reason to retain both, better documentation might be in order.
Same for GEOM_BSD and GEOM_PART_BSD.

Thank you.