message: indexcodec: Make sure codeaux_table sentinels are zero
  This will make sure we can use these as version data in the future.
  In the existing stream, they can be found by looking at the last two
  bytes of the encoded stream, so the version will have to be in the
  footer.
diff: @@ -170,6 +170,10 @@ size_t meshopt_encodeIndexBuffer(unsigned char* buffer, size_t buffer_size, cons
  // for now we keep it simple and use the table that has been generated based on symbol frequency on a training mesh set
  const unsigned char* codeaux_table = kCodeAuxEncodingTable;
  + // two last entries of codeaux_table are redundant - they are never referenced by the encoding
  + // make sure that they are both zero, since they can serve as version/other data in the future
  + assert(codeaux_table[14] == 0 && codeaux_table[15] == 0);
  +
  for (size_t i = 0; i < index_count; i += 3)
  {
  int fer = getEdgeFifo(edgefifo, indices[i + 0], indices[i + 1], indices[i + 2], edgefifooffset);
  