Revert "Fix cypclass refcount on arrays" to fix temps never being freed

This reverts commit 45d8df5a.

Cython/Compiler/ExprNodes.py

@@ -4356,13 +4356,6 @@ class IndexNode(_IndexingBaseNode):
             code.putln(
                 "%s = %s;" % (self.result(), rhs.result()))
 
-        if self.type.is_cyp_class:
-            # This hack is due to the fact cypclass objects are ref-counted, so
-            # they goes into temps, but their assignment code is a simple C assignment,
-            # which doesn't incref the temp.
-            # So we are effectively absorbing a reference in this case.
-            rhs.generate_post_assignment_code(code)
-        else:
         self.generate_subexpr_disposal_code(code)
         self.free_subexpr_temps(code)
         rhs.generate_disposal_code(code)