swift-package-manager

[PackageModel] Switch Module.recursiveDependencies to be well defined.

 - The results were previously unordered w.r.t. the dependency build order, this
   makes them always appear in build order.

 - I don't *think* anything was necessarily broken because of the previous
   order, but it is better to have it be well defined; this also eliminates some
   copy-paste code.