build: fix file paths after moving modules/@angular/* to packages/*

packages/core/testing/src/testing.ts

@@ -0,0 +1,21 @@
+/**
+ * @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
+ */
+
+/**
+ * @module
+ * @description
+ * Entry point for all public APIs of the core/testing package.
+ */
+
+export * from './async';
+export * from './component_fixture';
+export * from './fake_async';
+export * from './test_bed';
+export * from './before_each';
+export * from './metadata_override';
+export * from './private_export_testing';