Fix failing build.

Author: ZeroIntensity

Python/bytecodes.c

@@ -1104,9 +1104,10 @@ dummy_func(
                 (Py_TYPE(receiver_o) == &PyGen_Type || Py_TYPE(receiver_o) == &PyCoro_Type) &&
                 ((PyGenObject *)receiver_o)->gi_frame_state < FRAME_EXECUTING)
             {
+                _PyInterpreterFrame *gen_frame;
                 PyGenObject *gen = (PyGenObject *)receiver_o;
                 Py_BEGIN_CRITICAL_SECTION(gen);
-                _PyInterpreterFrame *gen_frame = &gen->gi_iframe;
+                gen_frame = &gen->gi_iframe;
                 STACK_SHRINK(1);
                 _PyFrame_StackPush(gen_frame, v);
                 gen->gi_frame_state = FRAME_EXECUTING;