More changes to use #ifndef PRODUCT ... #endif explicitly instead of relying on compiler magic.

runtime/vm/flags.h

Index: runtime/vm/flags.h
diff --git a/runtime/vm/flags.h b/runtime/vm/flags.h
index 81f594eb1f1e6d26fb3564207a10a29576dbe246..b30299c7a95adb7fec983fe1ffc93618d2dc66b4 100644
--- a/runtime/vm/flags.h
+++ b/runtime/vm/flags.h
@@ -1,4 +1,4 @@
-// Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
+// Copyright (c) 2012, the Dart project authors[.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
@@ -67,7 +67,9 @@ class Flags {
 
   static bool Initialized() { return initialized_; }
 
+#ifndef PRODUCT
   static void PrintJSON(JSONStream* js);
+#endif  // !PRODUCT
 
   static bool SetFlag(const char* name,
                       const char* value,
@@ -90,7 +92,9 @@ class Flags {
 
   static void PrintFlags();
 
+#ifndef PRODUCT
   static void PrintFlagToJSONArray(JSONArray* jsarr, const Flag* flag);
+#endif  // !PRODUCT
 
   // Testing needs direct access to private methods.
   friend void Dart_TestParseFlags();