Reduce wpi(4) diff to OpenBSD circa September 2007; mostly by following KNF.
The only functional changes in this commit are some %d to %u debugging printf
format specifier adjustments so as to match the OpenBSD code.
Use M_ZERO.  From OpenBSD if_wpi.c 1.53.
Rework /usr/share/doc.

Update the <bsd.doc.mk> infrastructure, and update the docs to match
the new infrastructure.

- Build and install text, ps, pdf, and/or html, not roff sources.

- Don't wire the chapter numbers into the build system, or use them in
the installed pathnames. This didn't matter much when the docs were a
museum, but now that we're theoretically going to start maintaining
them again, we're going to add and remove documents periodically and
having the chapter numbers baked in creates a lot of thrashing for no
purpose.

- Specify the document name explicitly, rather than implicitly in a
path. Use this name (instead of other random strings) as the name
of the installed files.

- Specify the document section, which is the subdirectory of
/usr/share/doc to install into.

- Allow multiple subdocuments. (That is, multiple documents in one
output directory.)

- Enumerate the .png files groff emits along with html so they can be
installed.

- Remove assorted hand-rolled rules for running roff and roff widgetry
and add enough variable settings to make these unnecessary. This
includes support for
   - explicit use of soelim
   - refer
   - tbl
   - pic
   - eqn

- Forcibly apply at least minimal amounts of sanity to certain
autogenerated roff files.

- Don't exclude USD.doc, SMM.doc, and PSD.doc directories from the
build, as they now actually do stuff.

Note: currently we can't generate pdf. This turns out to be a
nontrivial problem with no immediate solution forthcoming. So for now,
as a workaround, install compressed .ps as the printable form.
Reorg docs, part 1:
Move all the reference manuals to subdirs of /usr/share/doc/reference.
We have subdirs ref1-ref9, corresponding to man page sections 1-9.

Everything that's the reference manual for a program (sections 1, 6,
8), C interface (sections 2, 3), driver or file system (section 4),
format or configuration (section 5), or kernel internal interface
(section 9) belongs in here.

Section 7 is a little less clear: some things that might go in section
7 if they were a man page aren't really reference manuals. So I'm only
putting things in reference section 7 that are (to me) clearly
reference material, rather than e.g. tutorials, guides, FAQs, etc.
This obviously leaves some room for debate, especially without first
editing the docs with this distinction in mind, but if people hate
what I've done things can always be moved again.

Note also that while roff macro man pages traditionally go in section
7, I have put all the roff documentation (macros, tools, etc.) in one
place in reference/ref1/roff. This will make it easier to find and
also easier to edit it into some kind of coherent form.
Reorg docs, part 2:
Rename the following reference documents to match their programs:
   shell -> sh
   viref -> vi

and rename the following to match their topic better:
   ipctut -> sockets
   ipc -> sockets-advanced

Also, the old "timed" and "timedop" docs are now ref5/timed and
ref8/timed respectively, as the first of these documented the
protocol.
Reorg docs, part 3:
Move the documents that are papers to /usr/share/doc/papers.
Give them suitable names (including the author and year).

The key property of papers that distinguishes them from documentation
is that they're historical: they're published at a particular time and
aren't updated or maintained. (Except cosmetically.)

We should only ship papers that are of interest to users, either for
historical perspective or because they're the original research
writeup of stuff that went into the system and is still pertinent.

The ffs papers clearly meet this standard; the other one here (about
passwords, in 1978) is probably past its sell-by date.
Remove HTMLDOCDIR; it is no longer used (and doesn't fit the docs
scheme) and it was never honored anyway except in a couple places.
Update the distrib-dirs mtree specification for the new /usr/share/doc
layout.
Update set lists for /usr/share/doc reorg.
Add a file to help keep track of what's where and what we never
actually had.
Drop entries for LLVM/Clang older than 3.4.
Provide a basic implementation of __atomic_load_* and __atomic_store_*,
used by GCC and LLVM as backing for C11/C++11 atomics, if the hardware
is not known to have corresponding features. Include it on ARM as LLVM
and libc++ hit it when compiled for ARMv4.
Remove atomic hack for ARM, libc now provides the missing symbols.
Implement error checking in m_xbyte() and check for errors after m_xbyte() call.
Reuse (len - k) expression in m_xword() and m_xhalf() to give an optimization
hint to a compiler.

When m_xbyte() didn't exist, bpf_filter() handled out-of-bounds BPF_B loads
correctly because "return 0" inside MINDEX() was aborting filter programs.
After the change that added m_xbyte() zero values were passed to A or X
registers instead of aborting a filter program.
Put /usr/share/doc/reference/ref1/make in the right list. The dirs are
always created.
Remove stray .if make(insatll).

I would really like to know why this didn't fail the clean build I ran
last night.
remove .if make(install)
these are seriously bad juju
remove .if make(install)
When building GCC with Clang, disable optimizations for tree.c until I
can figure out what is responsible for the miscompilation.
Add unused memory model argument to make GCC happy.