INT 21 U - OS/2 v1.x FAPI - "DosQMaxEASize" - GET MAXIMUM SIZE OF EXTENDED ATTR
	AX = 6F00h
	DS:SI -> DWORDDoubleword; four bytes.	 Commonly used to hold a 32-bit segment:offset or selector:offset address. buffer for maximum size of an extended attribute
Return: CF clear if successful
	    AX = 0000h
	    buffer filled
	CF set on error
	    AX = error code
Note:	also supported by OS/2 v2.0+ Virtual DOS Machines
SeeAlso: AX=5703h,AX=6C01h,AH=6Eh"OS/2"