Reproduce pipe() problems

[dominykas]

Reason for the change

For now, this just adds a reproduction test-case for https://github.com/rethinkdb/rethinkdb-ts/issues/108

Checklist

• [x] I have read and agreed to the RethinkDB Contributor License Agreement

[dominykas]

(closing - will reopen from a different branch, as I'd like to use my main for forking this).