INT 21 - Phar Lap 386/DOS-Extender - VIRTUAL MEMORY MANAGEMENT - PAGE LOCKING

	AX = 252Bh
	BH = function
	    05h lock pages
	    06h unlock pages
	BL = address type
	    00h linear address
		ECX = linear start address of memory region
	    01h segmented address
		ES:ECX -> start of memory region
	EDX = size of memory region in bytes
Return: CF clear if successful
	CF set on error
Note:	this function is also supported by FlashTek X-32VM; if X-32 is not
	  using virtual memory, this function always succeeds