MSC: void *_expand( void *block, size_t size )
	  MSC: void far *_fexpand( void far *block, size_t size )
	  MSC: void near *_nexpand( void near *block, size_t size )

	  MSC: void _based(void) *_bexpand( _segment seg,
		    void _based(void) *block, size_t size )


	- prototype in malloc.h

	- block = pointer to previously allocated memory block
	- size = new size in bytes
	- seg = based segment value
	- returns pointer to reallocated memory block on success or NULL
	  if not;  (_bexpand returns -1 on failure)