gallium: try and update r300 and nv drivers for tgsi changes

gallium: try and update r300 and nv drivers for tgsi changes

It would be nice if these drivers built under the linux-debug header
so that these types of interface changes can be minimally propogated
into those drivers by people without the hardware.  They don't have to
generate a working driver -- though a command-dumping winsys would be
an excellent for regression checking.