[osx] Fix build on Xcode 6.4

bin/render.cpp

@@ -9,17 +9,12 @@
 #include <mbgl/storage/default_file_source.hpp>
 #include <mbgl/storage/sqlite_cache.hpp>
 
-#pragma clang diagnostic push
 #pragma GCC diagnostic push
-#ifdef __clang__
-#pragma clang diagnostic ignored "-Wunused-local-typedefs"
-#else
+#pragma GCC diagnostic ignored "-Wunknown-pragmas"
 #pragma GCC diagnostic ignored "-Wunused-local-typedefs"
 #pragma GCC diagnostic ignored "-Wshadow"
-#endif
 #include <boost/program_options.hpp>
 #pragma GCC diagnostic pop
-#pragma clang diagnostic pop
 
 namespace po = boost::program_options;