在JSX中的使用报错

使用了官网的配置，在render函数中这样写
```javascript
render: (h, params) => (

出现如下提示：
```
ReferenceError: Button is not defined
at Object.render (eval at ./node_modules/babel-loader/lib/index.js!./node_modules/vue-loader/lib/selector.js?type=script&index=0!./node_modules/iview-loader/index.js?{"prefix":true}!./src/views/page/table-list.vue (10.9c8c75d4e48bdc98cd45.hot-update.js:7), :129:15)
at render (iview.js?0536:5107)
at createFunctionalComponent (vue.runtime.esm.js?ff9b:4006)
at createComponent (vue.runtime.esm.js?ff9b:4178)
at _createElement (vue.runtime.esm.js?ff9b:4359)
at createElement (vue.runtime.esm.js?ff9b:4296)
at vm._c (vue.runtime.esm.js?ff9b:4412)
at Proxy.render (iview.js?0536:29651)
at VueComponent.Vue._render (vue.runtime.esm.js?ff9b:4470)
at VueComponent.updateComponent (vue.runtime.esm.js?ff9b:2761)
```

Start by reproducing the JSX example from the issue in src/views/page/table-list.vue and inspect the iview-loader, babel-loader, and vue-loader path shown in the stack trace. Trace why the generated render function refers to Button without a definition, then verify that the documented JSX usage renders without the ReferenceError.

Written by the indexing model from the issue text.