htl: Add wrapper header for <semaphore.h> with hidden __sem_post

This is required to avoid a check-localplt failure due to a
sem_post call through the PLT.

Reviewed-by: Samuel Thibault <samuel.thibault@ens-lyon.org>

sysdeps/htl/include/semaphore.h

@@ -0,0 +1,9 @@
+#ifndef	_SEMAPHORE_H
+#include_next <semaphore.h>
+
+#ifndef _ISOMAC
+extern __typeof (sem_post) __sem_post;
+libpthread_hidden_proto (__sem_post)
+#endif
+
+#endif

sysdeps/htl/sem-post.c

@@ -64,5 +64,5 @@ __sem_post (sem_t *sem)
 
   return 0;
 }
-
+libpthread_hidden_def (__sem_post)
 strong_alias (__sem_post, sem_post);

sysdeps/htl/sem-timedwait.c

@@ -167,7 +167,7 @@ out_locked:
     {
       if (ret == 0 && ctx.cancel_wake == 0)
 	/* We were cancelled while waking up with a token, put it back.  */
-	sem_post (sem);
+	__sem_post (sem);
 
       __pthread_exit (PTHREAD_CANCELED);
     }