Coreaudio: check if input/output devices have enough channels. Fail if the number of channels is less than requested via nchnls or nchnls_i. Without this, coreaudio fails silently and hangs. With this fix coreaudio has the same behaviour as portaudio on macOS
Coreaudio: check if input/output devices have enough channels.
Fail if the number of channels is less than requested via nchnls
or nchnls_i. Without this, coreaudio fails silently and hangs.
With this fix coreaudio has the same behaviour as portaudio on
macOS

csound/csound,csound/csound,csound/csound,csound/csound,csound/csound,csound/csound,csound/csound,csound/csound,csound/csound,csound/csound