SimVariable: add a new property 'category'.
SimVariable: add a new property 'category'.

tyb0807/angr,angr/angr,schieb/angr,tyb0807/angr,iamahuman/angr,tyb0807/angr,schieb/angr,angr/angr,iamahuman/angr,angr/angr,schieb/angr,iamahuman/angr