[Nouveau] [Patches] mesa/nv30: Diverse set of patches that improve NV3x render quality V3

[Roy Spliet]

Restored the original placement of texcoords in nv30_state.h. The other proposal (removing the fp->texcoords assignment in nvfx_fragprog_emit) breaks texturing in general and as such is not altered. Try running gnome-shell with that line commented out and see what I mean :-)

[2/3]: Quick ad-hoc fix for null-ptr deref, introduced by userbufs.