Log Message:
This doesn't use anything particularly specific other than opening
/dev/audio, as far as I can tell, so lift the narrow ONLY_FOR_PLATFORM
restriction.

(But, based on things I saw while going through audio/, mark it
NOT_FOR_PLATFORM on Interix.)

If you try it on Linux or whatever and it doesn't work, let me know or
file a PR and I'll attend to it or mark it broken.