The following operators currently fail tests that were introduced in #5652 and those failing tests are currently skipped:

• catchError - see fix(catchError): inner synchronous observables will properly terminate #5655
• exhaust - see test: enable now-passing firehose tests #5743
• exhaustMap - see test: enable now-passing firehose tests #5743
• multicast
• raceWith - see test: enable now-passing firehose tests #5743
• refCount
• repeat - see Issue/5739 smaller operator creation #5742
• repeatWhen - see Issue/5739 smaller operator creation #5742
• retry - see Issue/5739 smaller operator creation #5742
• retryWhen - see test: enable now-passing firehose tests #5743
• share
• shareReplay
• single - see test: enable now-passing firehose tests #5743
• skipLast - see test: enable remaining synchronous firehose tests #5749
• throttle - see test: enable remaining synchronous firehose tests #5749
• timeout - see test(timeout): enable skipped test #5748
• timeoutWith - see test(timeout): enable skipped test #5748

The tests are marked with // TODO: fix firehose unsubscription comments.

Update: it's not going to be possible to make the multicast-based tests pass.