045 source block in pipeline

// TEST: Source block inside a pipeline/continuation
//
// When a Source block event is invoked INSIDE a continuation (not top-level),
// the parser should still detect and parse the Source block correctly.
//
// Top-level works:
//   ~event { source }      <-- WORKS
//
// Inside pipeline should also work:
//   ~first_event()
//   | branch |> second_event {
//       source content here
//     }
//     | next |> ...   <-- THIS IS WHAT WE'RE TESTING
//

~import std/io

// First: void event to start a pipeline
~tor setup {}

~proc setup|zig {
}

// Now use print.blk INSIDE the pipeline continuation
~setup() |> std/io:print.blk {
    Hello from inside a pipeline!
  }