message: swoole serialize support cycle ref
diff: @@ -995,6 +995,7 @@ try_again:
  if (GC_IS_RECURSIVE(ht))
  {
  + ((SBucketType*) (buffer->buffer + p))->data_type = IS_NULL;//reset type null
  php_error_docref(NULL TSRMLS_CC, E_NOTICE, "the array has cycle ref");
  }
  else
  