Remove quite a bit of the old parser representation logic.

jedi/evaluate/__init__.py

@@ -136,7 +136,6 @@ class Evaluator(object):
         if seek_name:
             types = finder.check_tuple_assignments(types, seek_name)
 
-        ass_details = stmt.assignment_details
         first_operation = stmt.first_operation()
         if first_operation not in ('=', None) and not isinstance(stmt, er.InstanceElement):  # TODO don't check for this.
             # `=` is always the last character in aug assignments -> -1