eina: fix support for system requiring _XOPEN_SOURCE to use spinlock and barrier.

src/lib/eina/eina_inline_lock_posix.x

@@ -19,6 +19,12 @@
 #ifndef EINA_INLINE_LOCK_POSIX_X_
 #define EINA_INLINE_LOCK_POSIX_X_
 
+#ifdef _XOPEN_SOURCE
+# define EINA_XOPEN_SOURCE _XOPEN_SOURCE
+# undef _XOPEN_SOURCE
+#endif
+#define _XOPEN_SOURCE 600
+
 #ifdef EINA_HAVE_POSIX_SPINLOCK
 # include <sched.h>
 #endif
@@ -650,4 +656,10 @@ eina_spinlock_free(Eina_Spinlock *spinlock)
 #endif
 }
 
+#undef _XOPEN_SOURCE
+// This is necessary to let third party still define this macro
+#ifdef EINA_XOPEN_SOURCE
+# define _XOPEN_SOURCE EINA_XOPEN_SOURCE
+#endif
+
 #endif