Fix compile error in executor_cases.c.h

Author: colesbury

Python/bytecodes.c

@@ -4807,7 +4807,7 @@ dummy_func(
  #endif
  _PyExecutorObject *executor;
  if (target->op.code == ENTER_EXECUTOR) {
- PyCodeObject *code = (PyCodeObject *)frame->f_executable;
+ PyCodeObject *code = _PyFrame_GetCode(frame);
  executor = code->co_executors->executors[target->op.arg];
  Py_INCREF(executor);
  }