linux.hpp in passenger-5.0.25

- old
+ new

@@ -70,10 +70,12 @@
 #endif
 
 // boilerplate code:
 #define BOOST_HAS_UNISTD_H
 #include <boost/config/posix_features.hpp>
+#ifdef __USE_GNU
 #define BOOST_HAS_PTHREAD_YIELD
+#endif
 
 #ifndef __GNUC__
 //
 // if the compiler is not gcc we still need to be able to parse
 // the GNU system headers, some of which (mainly <stdint.h>)