Fix BSD and macOS builds w.r.t. pthread_setname_np (bug#38632)

pthread_setname_np takes only a single argument on BSD and macOS,
and affects the current thread only.

* configure.ac: Add check for single-argument pthread_setname_np
* src/systhread.c (sys_thread_set_name): New (w32 and pthread versions).
(sys_thread_create): Remove name argument and name-setting.
(w32_beginthread_wrapper): Remove name-setting.
* src/systhread.h (sys_thread_create, sys_thread_set_name):
Update prototypes.
* src/thread.c (run_thread): Call sys_thread_set_name.
(Fmake_thread): Adapt call to sys_thread_create.
* src/thread.h (struct thread_state): Adjust comment.

1 files changed, 1 insertions, 2 deletions

diff --git a/src/thread.h b/src/thread.h
index e96a063a10b..a09929fa440 100644
--- a/src/thread.h
+++ b/src/thread.h
@@ -169,8 +169,7 @@ struct thread_state
      interrupter should broadcast to this condition.  */
   sys_cond_t *wait_condvar;
 
-  /* Thread's name in the locale encoding.  Actually used only on
-     WINDOWSNT.  */
+  /* Thread's name in the locale encoding.  */
   char *thread_name;
 
   /* This thread might have released the global lock.  If so, this is