Bugfix: ServerProfiler - don't emit thread tracks with only allocations in them - Handle "legal" case where we don't have any method marks on worker threads after frame start timestamp - Handle "legal" case where we get a thread profile for a thread that was stopped before the frame start - Handle "legal" case where we get empty thread profiles due to method filtering - Dead func removal This can be a controversial choice, as allocations do happen there, but it's not something we can interact with because there's not enough helpful information about them(for example, what if we filter out entire thread methods?). Tests: did 4 exports, wasn't able to find weird allocation records on different threads.