remove use of new/delete and use halide_malloc/halide_free for hexagon_host.cpp - windows build issue
remove use of new/delete and use halide_malloc/halide_free for hexagon_host.cpp - windows build issue

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