Temporary patch from Thomas Schwinge to fix libpthread bugs.

diff --git libpthread/sysdeps/mach/pt-thread-dealloc.c b/sysdeps/mach/pt-thread-dealloc.c
index 55d8c4d..0c4a4fc 100644
--- libpthread/sysdeps/mach/pt-thread-dealloc.c
+++ libpthread/sysdeps/mach/pt-thread-dealloc.c
@@ -38,4 +38,6 @@ __pthread_thread_dealloc (struct __pthread *thread)
      assert.  */
   __mach_port_destroy (__mach_task_self (),
 		       thread->wakeupmsg.msgh_remote_port);
+
+  thread->have_kernel_resources = 0;
 }
diff --git libpthread/sysdeps/mach/pt-thread-halt.c b/sysdeps/mach/pt-thread-halt.c
index 973cde1..a9c3858 100644
--- libpthread/sysdeps/mach/pt-thread-halt.c
+++ libpthread/sysdeps/mach/pt-thread-halt.c
@@ -32,6 +32,21 @@
 void
 __pthread_thread_halt (struct __pthread *thread)
 {
-  error_t err = __thread_terminate (thread->kernel_thread);
-  assert_perror (err);
+  if (thread->have_kernel_resources)
+    {
+      if (thread == _pthread_self ())
+	{
+	  while (1)
+	    {
+	      error_t err = __thread_suspend (thread->kernel_thread);
+	      assert_perror (err);
+	      assert (! "Failed to suspend self.");
+	    }
+	}
+      else
+	{
+	  error_t err = __thread_terminate (thread->kernel_thread);
+	  assert_perror (err);
+	}
+    }
 }