Source §3 Concurrent: Ellipses not supported

[martin-henz]

Source §3 Concurrent does not support ellipses syntax.

Supporting ellipses will allow us to close a gap in SICP JS 3.4, and it will allow us to move the function stream() from stdlib/stream.ts to stdlib/stream.prelude.ts, and remove stream.ts.

[leeyi45]

Resolved by #1745