INT 31 P - DPMI 0.9+ - DISCARD PAGES
        AX = 0701h
        BX:CX = starting linear page number
        SI:DI = number of pages to discard
Return: ???
Note:   although marked as reserved in versions 0.9 and 1.0 of the DPMI
          specification, this function is called by MS Windows TASKMAN,
          PROGMAN, and KERNEL
SeeAlso: AX=0703h