refactor: move angular source to /packages rather than modules/@angular

packages/core/test/dev_mode_spec.ts

@@ -0,0 +1,15 @@
+/**
+ * @license
+ * Copyright Google Inc. All Rights Reserved.
+ *
+ * Use of this source code is governed by an MIT-style license that can be
+ * found in the LICENSE file at https://angular.io/license
+ */
+
+import {isDevMode} from '@angular/core';
+
+export function main() {
+  describe('dev mode', () => {
+    it('is enabled in our tests by default', () => { expect(isDevMode()).toBe(true); });
+  });
+}