Merge pull request #12176 from bz2/mangle_private_members

Allow private class members to be mangled

config/webpack-config-legacy-build.js

@@ -1,4 +1,6 @@
 const path = require('path');
+const TerserPlugin = require('terser-webpack-plugin');
+
 module.exports = {
   entry: './build/index.js',
   devtool: 'source-map',
@@ -31,6 +33,16 @@ module.exports = {
       ol: path.resolve('./build/ol'),
     },
   },
+  optimization: {
+    minimizer: [
+      new TerserPlugin({
+        terserOptions: {
+          // Mangle private members convention with underscore suffix
+          mangle: {properties: {regex: /_$/}},
+        },
+      }),
+    ],
+  },
   output: {
     path: path.resolve('./build/legacy'),
     filename: 'ol.js',