The first iteration attempted to flatten out ^/tests/sys/compat32, since
we'll never need to install more than one set of compat32 tests for any
given architecture -- the arch directory ends up being generally
redundant. Unfortunately, the way it was accomplished was incredibly
fragile and relied on an arch subdir providing sys/compat32/Kyuafile.
Fix it by restructuring to operate generally like the libc build; the
^/tests/sys/compat32 Makefile contains the necessary boilerplate to put
a Kyuafile in the right directory regardless of what tests we end up
including, the arch subdirectory provides a Makefile.inc with the bits
needed for building.
The existing compat32 tests remain disabled until a path forward is
solidified for dealing with the build issues.