Difference between InternalFireQueuedAsync and InternalFireQueued

[NickNightingale]

Looking at the implementation of InternalFireQueuedAsync and InternalFireQueued, there seems to be a significant difference:

1. InternalFireQueued always queues the trigger, so all triggers will be fired FIFO.
2. InternalFireQueuedAsync does not queue the current trigger if _firing is false. It then fires the current trigger first, followed by anything in the FIFO queue, so the triggers will not be called in the order in which InternalFireQueuedAsync was called.

Is that the intended behaviour and if so why?