Detect when there is only single prefetch op needed on higher dimension boxes
Detect when there is only single prefetch op needed on higher dimension boxes

kgnk/Halide,psuriana/Halide,psuriana/Halide,kgnk/Halide,kgnk/Halide,kgnk/Halide,ronen/Halide,ronen/Halide,psuriana/Halide,ronen/Halide,kgnk/Halide,ronen/Halide,ronen/Halide,psuriana/Halide,kgnk/Halide,ronen/Halide,psuriana/Halide,psuriana/Halide,psuriana/Halide,kgnk/Halide,ronen/Halide,kgnk/Halide,ronen/Halide