Add linux -> windows cross-compilation bots (for x64 and arm64)

[alexmarkov]

Apparently g3 builds AOT snapshots on Linux when targeting Windows. However, such cross-OS compilation is not tested on Dart SDK bots, which results in the g3 breakages. It looks like Dart SDK should support this configuration more consistently and test it more thoroughly.

So, it would be nice to add AOT Windows bots with cross-compilation - build AOT snapshot on Linux but run application on Windows, for x64 and arm64. We can also replace some of the existing AOT Windows bots with cross-compilation bots.

@athomas @mraleph @dcharkes