Continue removing unsupported target operating system support code.

There are a lot of target operating systems that Mozilla at least theoretically supported.

While I will remain open to re-adding support for these, except Macintosh, I would require that they be done within the context of the current modern requirements of said target OS not hacked, doublehacked, half-assed, and triple hacked over the past 20 years with very little testing or quality assurance.

Please file a new issue if you wish to make a strong commitment to re-add and support any removed target operating systems.

#6 Continue removing unsupported target operating system support code.