Snippets for libvpx 1.17.0 from Alpine armv7

Sourced from https://build.alpinelinux.org/buildlogs/build-edge-armv7/community/libvpx/libvpx-1.17.0-r0.log.

• /usr/include/fortify/string.h:81:16: warning: '__builtin_memset' specified bound between 3221225504 and 4294967295 exceeds maximum object size 2147483647 [-Wstringop-overflow=]
     81 |         return __builtin_memset(__d, __c, __n);
        |                ^
  

• vpx/src/vpx_image.c:277:27: warning: 'free' called on pointer 'in_7(D)' with nonzero offset 112 [-Wfree-nonheap-object]
    277 |     if (img->self_allocd) free(img);
        |                           ^