Add missing field for `TEXTURE_COPY_LOCATION`
Add missing field for `TEXTURE_COPY_LOCATION`

Add missing anonymous union field for [D3D12_TEXTURE_COPY_LOCATION ](https://docs.microsoft.com/en-us/windows/win32/api/d3d12/ns-d3d12-d3d12_texture_copy_location):
```C
union {
    D3D12_PLACED_SUBRESOURCE_FOOTPRINT PlacedFootprint;
    UINT                               SubresourceIndex;
  };
```
gingerBill/Odin,gingerBill/Odin,gingerBill/Odin,gingerBill/Odin