This now passes all of the following, either
when directly bouncing or when re-recording via physical loopback:
* record w/preroll
* record w/count-int
* loop record at 00:00:00
* loop record starting >> 00:00:00
* punch record at 00:00:00
* punch record > 00:00:00
* rec-arm while looping (!)
* repeatedly rec-arm/disarm while rolling