Split NT priorities according to whether we have stoppers
Split NT priorities according to whether we have stoppers

In this CL, there aren't any behavior changes because we rank the split
priorities the same way.

abortz/saycbridge,abortz/saycbridge,eseidel/saycbridge,eseidel/saycbridge,abortz/saycbridge,abortz/saycbridge,eseidel/saycbridge,abortz/saycbridge