nv60: Add slct instructions.
nv60: Add slct instructions.

They actually have the full set of comparison operations available, and
compare to 0.

kfractal/envytools,hakzsam/envytools,hakzsam/envytools,pierremoreau/envytools,kfractal/envytools,grate-driver/envytools,karolherbst/envytools,kfractal/envytools,envytools/envytools,MoochMcGee/envytools,grate-driver/envytools,kfractal/envytools,envytools/envytools,hakzsam/envytools,grate-driver/envytools,envytools/envytools,pierremoreau/envytools,karolherbst/envytools,karolherbst/envytools,pierremoreau/envytools,MoochMcGee/envytools,MoochMcGee/envytools,grate-driver/envytools,hakzsam/envytools,grate-driver/envytools,hakzsam/envytools,pierremoreau/envytools,kfractal/envytools,pierremoreau/envytools,karolherbst/envytools,envytools/envytools,MoochMcGee/envytools,envytools/envytools,karolherbst/envytools,MoochMcGee/envytools