test: change polyfills in hello-world-app which causes rebuilds TS worker to fail

Author: alan-agius4

tests/angular_devkit/build_angular/hello-world-app/package.json

@@ -23,7 +23,6 @@
     "@angular/platform-browser": "^6.0.0-rc.0",
     "@angular/platform-browser-dynamic": "^6.0.0-rc.0",
     "@angular/router": "^6.0.0-rc.0",
-    "core-js": "^2.4.1",
     "rxjs": "~6.2.0",
     "zone.js": "^0.8.19"
   },

tests/angular_devkit/build_angular/hello-world-app/src/polyfills.ts

@@ -25,49 +25,46 @@
  * BROWSER POLYFILLS
  */
 
-/** IE9, IE10 and IE11 requires all of the following polyfills. **/
-// import 'core-js/es6/symbol';
-// import 'core-js/es6/object';
-// import 'core-js/es6/function';
-// import 'core-js/es6/parse-int';
-// import 'core-js/es6/parse-float';
-// import 'core-js/es6/number';
-// import 'core-js/es6/math';
-// import 'core-js/es6/string';
-// import 'core-js/es6/date';
-// import 'core-js/es6/array';
-// import 'core-js/es6/regexp';
-// import 'core-js/es6/map';
-// import 'core-js/es6/weak-map';
-// import 'core-js/es6/set';
-
 /** IE10 and IE11 requires the following for NgClass support on SVG elements */
 // import 'classlist.js';  // Run `npm install --save classlist.js`.
 
-/** IE10 and IE11 requires the following for the Reflect API. */
-// import 'core-js/es6/reflect';
-
-
-/** Evergreen browsers require these. **/
-// Used for reflect-metadata in JIT. If you use AOT (and only Angular decorators), you can remove.
-import 'core-js/es7/reflect';
-
-
 /**
- * Required to support Web Animations `@angular/platform-browser/animations`.
- * Needed for: All but Chrome, Firefox and Opera. http://caniuse.com/#feat=web-animation
- **/
+ * Web Animations `@angular/platform-browser/animations`
+ * Only required if AnimationBuilder is used within the application and using IE/Edge or Safari.
+ * Standard animation support in Angular DOES NOT require any polyfills (as of Angular 6.0).
+ */
 // import 'web-animations-js';  // Run `npm install --save web-animations-js`.
 
-
+/**
+ * By default, zone.js will patch all possible macroTask and DomEvents
+ * user can disable parts of macroTask/DomEvents patch by setting following flags
+ * because those flags need to be set before `zone.js` being loaded, and webpack
+ * will put import in the top of bundle, so user need to create a separate file
+ * in this directory (for example: zone-flags.ts), and put the following flags
+ * into that file, and then add the following code before importing zone.js.
+ * import './zone-flags.ts';
+ *
+ * The flags allowed in zone-flags.ts are listed here.
+ *
+ * The following flags will work for all browsers.
+ *
+ * (window as any).__Zone_disable_requestAnimationFrame = true; // disable patch requestAnimationFrame
+ * (window as any).__Zone_disable_on_property = true; // disable patch onProperty such as onclick
+ * (window as any).__zone_symbol__UNPATCHED_EVENTS = ['scroll', 'mousemove']; // disable patch specified eventNames
+ *
+ *  in IE/Edge developer tools, the addEventListener will also be wrapped by zone.js
+ *  with the following flag, it will bypass `zone.js` patch for IE/Edge
+ *
+ *  (window as any).__Zone_enable_cross_context_check = true;
+ *
+ */
 
 /***************************************************************************************************
  * Zone JS is required by default for Angular itself.
  */
 import 'zone.js/dist/zone';  // Included with Angular CLI.
 
 
-
 /***************************************************************************************************
  * APPLICATION IMPORTS
  */