Code the IRRACX01 exit routine to be reentrant and refreshable.

Link-edit IRRACX01 exit routines with AMODE(31) or AMODE(ANY) and with RMODE(24) or RMODE(ANY).

The exit must be aware that it can receive an ENVR object, or an ACEE created from an ENVR object, that originated on another system. If an ACEE was created from an ENVR object that originated on another system, the bit ACEEXNVR is set. If exits need to know the exact origin of the ACEE information, they can store this information in the installation data field pointed to by ACEEIEP.