INT 31 P - DPMIsee DOS Protected-Mode Interface 0.9+ - LOCK SELECTOR
	AX = 0004h
	BX = selector to lock (prevent paging)
Return: ???
Note:	although marked as reserved in versions 0.9 and 1.0 of the DPMIsee DOS Protected-Mode Interface
	  specification, this function is called by MS Windows TASKMAN,
	  PROGMAN, and KERNEL
SeeAlso: AX=0005h,AX=0600h