Bump RC_SPAN_HEIGHT_BITS from 13 to 16 Increasing the bits used, will yield more accurate height information in the generated navmesh polys. This does not change the size of rcSpan on x64 plattforms. (See https://godbolt.org/z/4eKq45daK) x64 is the only platform we are targeting for s&box and Rust. Therefore, this is free accuracy improvement without perf or memory impact.