fix(suspense): misusing DOM Comment element constructor as a vnode type (#4451)

Author: liximomo

packages/runtime-core/src/components/Suspense.ts

@@ -6,6 +6,7 @@ import {
   openBlock,
   closeBlock,
   currentBlock,
+  Comment,
   createVNode
 } from '../vnode'
 import { isFunction, isArray, ShapeFlags, toNumber } from '@vue/shared'