legion: Fix for equal partition shim for empty subregions.
legion: Fix for equal partition shim for empty subregions.

StanfordLegion/legion,sdalton1/legion,chuckatkins/legion,StanfordLegion/legion,chuckatkins/legion,StanfordLegion/legion,sdalton1/legion,StanfordLegion/legion,chuckatkins/legion,sdalton1/legion,sdalton1/legion,sdalton1/legion,StanfordLegion/legion,chuckatkins/legion,sdalton1/legion,StanfordLegion/legion,StanfordLegion/legion,chuckatkins/legion,chuckatkins/legion,chuckatkins/legion,StanfordLegion/legion