- Hard patch removes FATAL/PANIC from client_message_level_options in guc.c, which also seems to make sense in regard to it's double-usage with trace_recovery_messages.
- Soft patch keeps FATAL/PANIC in client_message_level_options but coerces client_min_messages to ERROR when set to FATAL/PANIC and issues a warning. This also exports error_severity from elog.c to retrieve severity -> text mappings for the warning message.