message: improve:add local variable declaration
diff: @@ -327,6 +327,7 @@ export function createPatchFunction (backend) {
  function removeAndInvokeRemoveHook (vnode, rm) {
  if (isDef(rm) || isDef(vnode.data)) {
  + let i
  const listeners = cbs.remove.length + 1
  if (isDef(rm)) {
  // we have a recursively passed down rm callback
  