hdf5: make regent test actually test stuff
hdf5: make regent test actually test stuff

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