Possible memory leak-- processPromiseRejections never called? #262

After migrating from express to uwebsockets, i noticed a memory leak caused by node holding onto unhandled rejections and never flushing them

The pendingUnhandledRejections array is emptied when processPromiseRejections is called: https://github.com/nodejs/node/blob/c9b93e234454322ac0b7a6cd29d394f428f3e37d/lib/internal/process/promises.js#L171

It should get called every tick here: https://github.com/nodejs/node/blob/68abaab8baac203833889c9106abf6fe82a5900f/lib/internal/process/task_queues.js#L98

Perhaps the task queue is never empty, so !queue.isEmpty() || processPromiseRejections() always shortcircuits? Any guidance appreciated