This also reverts 768d8362cd since it causes crashes
with various plugins (eg. surge.vst3).
Ardour now provides AudioBusBuffers for all audio I/O busses,
regardless of Ardour using those busses.
This fixes crashes of plugins that ignore ProcessData::numInputs
or ProcessData::numOutputs. Those plugins are expected to check
numChannels and channelBuffers for those excess channels, which are
0, NULL for unused busses.
ProcessData numInputs, numOutputs does correctly reflect actual
busses that are in-use (at most one main and one aux for each direction).
Robin Gareus
4a9a4bf3de
