INT 31 P - DPMI 1.0+ - GET REAL MODE EXTENDED PROCESSOR EXCEPTION HANDLER
        AX = 0211h
        BL = exception number (00h-1Fh)
Return: CF clear if successful
            CX:(EDX) = selector:offset of exception handler
        CF set on error
            AX = error code (8021h) (see AX=0000h)
Notes:  returns address of protected-mode handler for real-mode exception
        DPMI host performs a switch to protected mode, reflects the exception
          to the virtual machine's primary client, and returns to real mode
          on the handler's completion
SeeAlso: AX=0210h,AX=0213h