)
Call NESL function RegisterEventProducer with:
	BX = 0001h
	ES:SI -> Producer Event Control Block (PECB) (see #03021)
Return: AX = completion code (0000h, 8005h, 8008h) (see #03019)
	ES:SI -> still points to PECB
	BP,DS,STACK preserved
Desc:	Allows a module to register as a producer of a given event class
Note:	PECB_ClassName and PECB_Flags must be filled in on entry
SeeAlso: #02870,#03015,#03016,#03017