More reliably link libpng for tutorials
More reliably link libpng for tutorials


Former-commit-id: 274c0d3e53fb0fb4fe8748402cab3d7b8a436ff5
Trass3r/Halide,Trass3r/Halide,Trass3r/Halide,darkbuck/Halide,darkbuck/Halide,darkbuck/Halide,Trass3r/Halide,darkbuck/Halide,Trass3r/Halide,darkbuck/Halide,Trass3r/Halide,Trass3r/Halide,darkbuck/Halide,darkbuck/Halide