INT 31 - DPMI 0.9+ - GET DESCRIPTOR

	AX = 000Bh
	BX = LDT selector
	ES:(E)DI -> 8-byte buffer for copy of descriptor
Return: CF clear if successful
	    buffer filled
	CF set on error
	    AX = error code (DPMI 1.0+) (8022h) (see #03143)
Notes:	16-bit programs use ES:DI as pointer, 32-bit must use ES:EDI
	not supported by MS Windows 3.0 in Standard mode
SeeAlso: AX=000Ch