Function stbi__pnm_is16

lite/example/cpp_example/mge/cv/stb_image.h:8318–8322

}

static int stbi__pnm_is16(stbi__context* s) {
    if (stbi__pnm_info(s, NULL, NULL, NULL) == 16)
        return 1;
    return 0;
}
#endif

static int stbi__info_main(stbi__context* s, int* x, int* y, int* comp) {