fix various typos in compatibility, mainly in comments.

Note that compat_60 modules on i386 and amd64 once again include the
microcode-update functionality.

Note that the xen vs non-xen issue has been resolved by recent commit
from Chuck Silvers. (Also add xref to PR port-xen/53130 for history.)

Add another issue that I just remembered, from the time working on the
[pgoyette-compat] branch, regarding inability to get some XEN-related
modules to build.

Another issue, as identified on IRC/ICB

Add an entry to remind someone(tm) to review the need for WARNS=3 in
more than 100 modules' Makefile.

Expand the weak-symbol section to mention module unload issues. As
noted by martin@ on source-chages-d list.

Add an entry regarding weak symbols

Add a note about the (lack of) correspondence between a module's name and
the name of the file from which it is loaded.

Add some comments/suggestions from John Nemeth. Thanks!

Add reference to uwe's PR kern/52821

Add previous statement from core@ and add reference to earlier E-mail
discussion.

OK martin@

Add a note regarding the need for a common mechanism for defining and
building modules, whether built-in or separately-loadable.

Add comment about possibly prompting for "release" portion of module
path at boot-loader time.

Add an entry to discuss association of a kernel with its specific modules.

Prompted by recent Email discussion started by wiz (there have been many
earlier discussions on this topic, too).

Note desire to have a way to selectively build modules (and include them
from the modules/mi sets-list) based on "attributes" rather than having
to enumerate individual architectures on which to buil

Note desire to have a way to selectively build modules (and include them
from the modules/mi sets-list) based on "attributes" rather than having
to enumerate individual architectures on which to build and include.

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Fix typo.

Minor edit.

Add some additional comments resulting from my recent efforts to provide
ld(4) modularization.

Expand discussion a bit, and provide ppp as an example way to do things.

The ppp compressors are already being handled correctly. No new
work will be needed here.

Add some info regarding ppp

Add some more notes

Add a list of "module issues" based on an Email discussion between myself
and christos@