osxcross: remove support completely

2020-03-19: removing osxcross completely for now

Currently we use xcode 7.3, see mirror/xcode>. Upstream https://github.com/tpoechtrager/osxcross has added support for newer versions. At the time of writing (2020-01-15) up to 11 GM is known to work.

(side note: current job fails to build due to missing python dep)

Likely not useful: it appears some wine-ish thing exists that can be used to run xcode from cli, making compilation possible. This probably does not integrate properly with build system. https://github.com/darlinghq/darling

Edited Mar 19, 2020 by Melvin Vermeeren