INT 21 - DOS 2+ - RESIZE MEMORY BLOCK                                           
	AH = 4Ah
	BX = new size in paragraphs
	ES = segment of block to resize
Return: CF clear if successful
	CF set on error
	    AX = error code (07h,08h,09h) (see #01680 at AH=59h/BX=0000h)
	    BX = maximum paragraphs available for specified memory block
Notes:	under DOS 2.1-6.0, if there is insufficient memory to expand the block
	  as much as requested, the block will be made as large as possible
	DOS 2.1-6.0 coalesces any free blocks immediately following the block
	  to be resized
SeeAlso: AH=48h,AH=49h,AH=83h