Improve widening reduction test.
Improve widening reduction test.

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