Remove stderr files left by previous Spyder instances.

        This is only required on Windows because we can't
        clean up stderr files while Spyder is running on it.

def _remove_old_stderr_files(self):
        """
        Remove stderr files left by previous Spyder instances.

        This is only required on Windows because we can't
        clean up stderr files while Spyder is running on it.
        """
        if os.name == 'nt':
            tmpdir = get_temp_dir()
            for fname in os.listdir(tmpdir):
                if osp.splitext(fname)[1] == '.stderr':
                    try:
                        os.remove(osp.join(tmpdir, fname))
                    except Exception:
                        pass