Sync w/ upstream, hide pthread_atfork

libpthread/linuxthreads/pthread_atfork.c

@@ -44,8 +44,10 @@ extern void *__dso_handle __attribute__ ((__weak__));
 /* Hide the symbol so that no definition but the one locally in the
    executable or DSO is used.  */
 int
+#ifndef __pthread_atfork
 /* Don't mark the compatibility function as hidden.  */
 attribute_hidden
+#endif
 __pthread_atfork (prepare, parent, child)
      void (*prepare) (void);
      void (*parent) (void);
@@ -54,4 +56,8 @@ __pthread_atfork (prepare, parent, child)
   return __register_atfork (prepare, parent, child,
 			    &__dso_handle == NULL ? NULL : __dso_handle);
 }
+#ifndef __pthread_atfork
+extern int pthread_atfork (void (*prepare) (void), void (*parent) (void),
+			   void (*child) (void)) attribute_hidden;
 strong_alias (__pthread_atfork, pthread_atfork)
+#endif