Avoid including debug information in bin/%.s output, since the whole
point is to have easy-to-read assembler.

-Obinary build anyway, so it doesn't waste any space).

moment.

when make is invoked without arguments

directory.

are broken...  :)

with generated headers.

list for any build, e.g.
  make bin/pnic.dsk DEBUG=pci,pnic
This will drag in debugging-enabled versions of pci.c and pnic.c.