aco: Various fixes for function call support
Fixes a few issues I've come across when implementing function calls.
I'm pretty conservative with Cc: mesa-stable tags here, because I'm not sure these issues can occur outside of calls.
Due to an influx of spam, we have had to impose restrictions on new accounts. Please see this wiki page for instructions on how to get full permissions. Sorry for the inconvenience.
Fixes a few issues I've come across when implementing function calls.
I'm pretty conservative with Cc: mesa-stable tags here, because I'm not sure these issues can occur outside of calls.