webpack 配置babel-polyfill

入口文件写成数组形式

 entry: {    app: ['babel-polyfill', './src/main.js']  },

否则这种形式报错

   entry: {
   "babel-polyfill":"babel-polyfill",
    app: './src/main.js'
   },


only one instance of babel-polyfill is allowed