[dx88] Cull fix

[Ann and Jason Edmeades]

>> Michael - See if this helps with your map / figure problems...
>Sorry, but it doesn't helped. Also the other ones doesn't helped. The
fixme's
Ok, no worries - Its just the sort of bug which might have accounted for it.

These relate to render to texture, which I have put on hold for a bit as I
got stuck and bored...
>  fixme:d3d_surface:IDirect3DSurface8Impl_LockRect
>  fixme:d3d:IDirect3DDevice8Impl_SetRenderTarget

This can be ignored for now
>  fixme:d3d:IDirect3DDevice8Impl_ResourceManagerDiscardBytes

I think you said the map problem appears without the fixmes, so if it does,
then yes - Disable the dxtn support and grab the texture+backbuffer
screenshots and log of the single frame as I described before.

No rush - I know of enough bugs already, and I am tied up for a few days
since the last patches

Jason