[import] NetBSD audio support

[rmottola]

Transfer from old project. By @alarixnia
Source code here: https://cvsweb.netbsd.org/bsdweb.cgi/~checkout~/pkgsrc/www/arcticfox/files/cubeb_sun.c?rev=1.1&content-type=text/plain

It would probably be better to update the libcubeb dependency since this stuff has all been upstreamed to Mozilla. There are definitely API changes in cubeb between arcticfox and current firefox, though.

https://github.com/NetBSD/pkgsrc/blob/trunk/www/arcticfox/files/cubeb_sun.c

The configure and moz.build patches are here: https://github.com/NetBSD/pkgsrc/tree/trunk/www/arcticfox/patches

[rmottola]

Hi think the whole patch is this:
mozilla/gecko-dev@c145f83