When compiling the release version of WTF iOS for iPhone 6.0 Simulator, I get errors in FastMalloc.cpp. Any idea how to fix the errors?

.../XCode Projects/JavaScriptCore-iOS/WTF/wtf/FastMalloc.cpp:2477:8: error: private field 'pad_' is not used [-Werror,-Wunused-private-field]
char pad_[(64 - (sizeof(TCMalloc_Central_FreeList) % 64)) % 64];

.../XCode Projects/JavaScriptCore-iOS/WTF/wtf/FastMalloc.cpp:4544:31: error: private field 'm_reader' is not used [-Werror,-Wunused-private-field]
const RemoteMemoryReader& m_reader;