mappers: small default mapper tweak to hash function
mappers: small default mapper tweak to hash function

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