INT 21 - Phar Lap 386/DOS-Extender - GET PROTECTED-MODE INTERRUPT VECTOR

	AX = 2502h
	CL = interrupt number
Return: CF clear
	ES:EBX = CS:EIP of protected-mode interrupt handler
Note:	this function is also supported by FlashTek X-32VM
SeeAlso: AX=2503h,AX=2504h,INT 31/AX=0204h