Return `SwiftInfo` from `swift_{binary,test}` (#870)
Return `SwiftInfo` from `swift_{binary,test}` (#870)

This is similar to what `cc_binary` does. It helps to signify that the binary uses Swift, and for the case when it compiles its own sources, it exposes the `compilation_context` which isn't available any other way.
bazelbuild/rules_swift,bazelbuild/rules_swift