message: refactor: use isRegExp for safer check
diff: @@ -23,6 +23,7 @@ import {
  isUndef,
  isTrue,
  makeMap,
  + isRegExp,
  isPrimitive
  } from '../util/index'
  @@ -123,7 +124,7 @@ export function createPatchFunction (backend) {
  !(
  config.ignoredElements.length &&
  config.ignoredElements.some(ignore => {
  - return ignore instanceof RegExp
  + return isRegExp(ignore)
  ? ignore.test(tag)
  : ignore === tag
  })
  