Because the appropriate header wasn't included, there was no
prototype.  Not having a prototype is an error in C99, which caused
the test to indicate that there was no va_copy() on darwin.

This in turn caused jsprf.cpp to try to copy a va_list using
assignment.

This is invalid, so the compiler would normally return an error.

Somwhere in here, that error became a clang crash (not trivially
reproducable).

At the end of the day, ancient broken tests in config caused the
darwin Spidermonkey builds to fail.  The new patch fixes up the
configure tests, and darwin Synchronet builds are re-enabled.

This works on Buster at least... update the other config.guess file
the same as the top-level one, and always define JaegerSpew() so the
JIT stuff isn't broken.

Both sbbs-noskeeters and sbbs-build create sbbs-build.tgz
Hopefully this fixes it and doesn't just break it worser.

Also, allow tests to run as soon as jsdoor is done, and don't use
the artifact file, use the local copy instead.

hoping this doesn't leave an empty zip file laying aorund.

This may or may not actually work, and will certainly need a few
runs to build up the cache first.

Search in both /usr/local (Homebrew) and /opt/local (MacPorts) for
libraries.

Also, have the name of GNU make be an in option in CI so we can use
the Apple-provided make.

It builds and appears to run... not actually tested.

mingw32 has been dead for years, and is missing huge swaths of the
Windows APIs.  strerror_s() was the straw that broke the camels
back here, but there's a lot of hackery for it.

I'm not going to go through and actually remove the build support
yet since I may want to do the 1.2 SyncTERM release with it (though
likely not), but it's not long for this world.

Since we're modifying cryptlib anyway, we can't just dlopen any old
cryptlib library.  Require linking with the lib.  This will break
the MSVC build, so disable that for now.

We don't want CI to die because someone somewhere upgrade a compiler.

NOTE: CI does release builds, which means that -Wall is not enabled.
      WALL=1 could be added if we want that, but it's likely too
      soon to take that step.

Also, add a BUILD_ARGS variable so custom pipelines can be ran
for the templated job tree.

Just because I use them for SyncTERM releases doesn't mean we want
them for CI.