Fixed build errors with gcc and LLVM libc++

include/boost/move/detail/iterator_traits.hpp

@@ -24,10 +24,13 @@
 
 #include <cstddef>
 
-#if defined(__clang__) && defined(_LIBCPP_VERSION)
+#if defined(__clang__)
    #define BOOST_MOVE_CLANG_INLINE_STD_NS
    #pragma GCC diagnostic push
    #pragma GCC diagnostic ignored "-Wc++11-extensions"
+#endif
+
+#ifdef _LIBCPP_VERSION
    #define BOOST_MOVE_STD_NS_BEG _LIBCPP_BEGIN_NAMESPACE_STD
    #define BOOST_MOVE_STD_NS_END _LIBCPP_END_NAMESPACE_STD
 #else