tools: fix a bug in the python version of legion prof where multiple meta tasks for the same operation could shadow each other in the Variant data structure
tools: fix a bug in the python version of legion prof where multiple meta tasks for the same operation could shadow each other in the Variant data structure

StanfordLegion/legion,StanfordLegion/legion,StanfordLegion/legion,StanfordLegion/legion,StanfordLegion/legion,StanfordLegion/legion,StanfordLegion/legion,StanfordLegion/legion