Merge pull request #12181 from MoonE/webpack-fix-ie11

Build for ie11 again

config/webpack-config-legacy-build.js

@@ -3,6 +3,7 @@ module.exports = {
   entry: './build/index.js',
   devtool: 'source-map',
   mode: 'production',
+  target: ['web', 'es5'],
   module: {
     rules: [
       {

examples/webpack/config.js

@@ -8,7 +8,7 @@ const src = path.join(__dirname, '..');
 
 module.exports = {
   context: src,
-  target: 'web',
+  target: ['web', 'es5'],
   entry: () => {
     const entry = {};
     fs.readdirSync(src)