// in which case there is a subproblem-sized middle of sa that
	// we can reuse for temporary space (saTmp).
	// When recurse_64 is called from sais_8_64, oldTmp is length 512
	// (from text_64), and saTmp will typically be much larger, so we'll use saTmp.
	// When deeper recursions come back to recurse_64, now oldTmp is
	// the saTmp from the top-most recursion, it is typically larger than