Return empty sets instead of empty lists in get_objects_by_offset().
Return empty sets instead of empty lists in get_objects_by_offset().

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