Cross compile

[blendthink]

Currently application snapshots (as described here) can only be compiled for the architecture of the machine doing the compilation.
We will proceed with support when cross-compilation becomes possible.

• https://dart.dev/tools/dart-compile
• Allow AOT executables to be cross-compiled dart-lang/sdk#28617

FYI:

• https://medium.com/flutter-community/cross-compiling-dart-apps-f88e69824639
• https://blog.codemagic.io/cross-compiling-dart-cli-applications-with-codemagic/
• https://crushingcode.nisrulz.com/en/posts/cross-compilation-adventures-with-dart/