Fix handling of local variables in GO routine
Allow "OPT" and "AUX" variables in V6 GO routines, and give better diagnostic messages for the disallowed cases (required arguments in V6; any local variables in other versions). Fixes ZILF-210.
This instance will be upgraded to Heptapod 17.11.0rc1 on 2025-04-24 between 17:00 and 18:00 UTC+2
Allow "OPT" and "AUX" variables in V6 GO routines, and give better diagnostic messages for the disallowed cases (required arguments in V6; any local variables in other versions). Fixes ZILF-210.