Zig-gamedev project: DirectX 12 Mesh Shader benchmark

When drawing 200M triangles on GTX 1660:

    Mesh Shader emulating VS (no culling): ~26.8 ms
    VS with manual vertex fetching (no HW index buffer): ~50.2 ms
    VS with fixed function vertex fetching: ~24.8 ms

When drawing 200M triangles on RX 6800:

    Mesh Shader emulating VS (no culling): ~23.6 ms
    VS with manual vertex fetching (no HW index buffer): ~13.5 ms
    VS with fixed function vertex fetching: ~12.4 ms