gets Relay/Classic/Compat building

Reviewed By: fkgozali

Differential Revision: D5482765

fbshipit-source-id: 0a7c2b8d99256352f09b6510ec8ca1631425e232

Author: sahrens

Libraries/Utilities/DebugEnvironment.js

@@ -0,0 +1,18 @@
+/**
+ * Copyright (c) 2013-present, Facebook, Inc.
+ * All rights reserved.
+ *
+ * This source code is licensed under the BSD-style license found in the
+ * LICENSE file in the root directory of this source tree. An additional grant
+ * of patent rights can be found in the PATENTS file in the same directory.
+ *
+ * @providesModule DebugEnvironment
+ * @flow
+ */
+
+'use strict';
+
+module.exports = {
+  // When crippled, synchronous JS function calls to native will fail.
+  isCrippledMode: __DEV__ && !global.nativeCallSyncHook,
+};