Fix generic methods storage in type objects

trans/transpiler/phases/typing/stdlib.py

@@ -67,8 +67,9 @@ class StdlibVisitor(NodeVisitorSeq):
             ty.variadic = True
             #arg_types.append(TY_VARARG)
         if self.cur_class:
+            assert isinstance(self.cur_class, TypeType)
             if isinstance(self.cur_class.type_object, ABCMeta):
-                self.cur_class.gen_methods[node.name] = lambda t: ty.gen_sub(t, self.typevars)
+                self.cur_class.type_object.gen_methods[node.name] = lambda t: ty.gen_sub(t, self.typevars)
             else:
                 #     ty_inst = FunctionType(arg_types[1:], ret_type)
                 #     self.cur_class.args[0].add_inst_member(node.name, ty_inst)