@ts-check for bootstrap JS files

src/vs/code/electron-browser/sharedProcess/sharedProcess.js

@@ -3,6 +3,7 @@
  *  Licensed under the MIT License. See License.txt in the project root for license information.
  *--------------------------------------------------------------------------------------------*/
 
+//@ts-check
 'use strict';
 
 const bootstrapWindow = require('../../../../bootstrap-window');