only use diagnostic pragmas on gcc >=4.6

Change-Id: I8178cfe772d12acf30d025d947bfe2f98da9fd9f

boost/shared_ptr.hpp

@@ -14,13 +14,17 @@
 //  See http://www.boost.org/libs/smart_ptr/shared_ptr.htm for documentation.
 //
 
+#if __GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 6)
 // BEGIN ignore deprecation warnings about std::auto_ptr
 #pragma GCC diagnostic push
 #pragma GCC diagnostic ignored "-Wdeprecated-declarations"
+#endif
 
 #include <boost/smart_ptr/shared_ptr.hpp>
 
+#if __GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 6)
 // END ignore deprecation warnings about std::auto_ptr
 #pragma GCC diagnostic pop
+#endif
 
 #endif  // #ifndef BOOST_SHARED_PTR_HPP_INCLUDED