title: Remove exports variable from webpack generated code
body: <p>I am using Webpack to compile a TypeORM entity from TypeScript to JavaScript.
  The code that is being generated looks like this:</p>
  <pre class="lang-js prettyprint-override"><code>/******/ (() =&gt; { // webpackBootstrap
  /******/    &quot;use strict&quot;;
  var __webpack_exports__ = {};
  // This entry need to be wrapped in an IIFE because it uses a non-standard name for the exports (exports).
  (() =&gt; {
  var exports = __webpack_exports__;
  
  Object.defineProperty(exports, &quot;__esModule&quot;, ({ value: true }));
  class User1629307821282 {
      constructor() {
          this.name = &quot;User1629307821282&quot;;
      }
      async up(queryRunner) {
          await queryRunner.query(`
              CREATE TABLE \`database\`.\`user\` (
                  \`uuid\` char(36) NOT NULL,
                  \`first_name\` varchar(255) NOT NULL,
                  \`last_name\` varchar(255) NOT NULL,
                  \`is_active\` tinyint NOT NULL DEFAULT 1,
                  PRIMARY KEY (\`uuid\`)
               ) ENGINE=InnoDB`);
      }
      async down(queryRunner) {
          await queryRunner.query(`
              DROP TABLE \`database\`.\`user\`
          `);
      }
  }
  exports.default = User1629307821282;
  
  })();
  
  /******/ })()
  ;
  </code></pre>
  <p>When I run the command to run my migration, <code>typeorm migration:run</code>, it doesn't work, nothing happens.
  Now when I remove this piece of code at line 6, it does work and my migration is being executed:</p>
  <pre class="lang-js prettyprint-override"><code>var exports = __webpack_exports__;
  </code></pre>
  <p>Is there any option that causes that line to not appear in the generated JavaScript file?
  Or is there another way to achieve this? (I know I could just use <code>tsc</code> but I would like to use Webpack since I use this for everything in my project.)</p>
  <p>Thanks!</p>