Cygwin: cygthread: set thread name before calling thread func

When reusing a cygthread, the stub method fails to set the thread name
to the new name.  The name is only set when actually creating the
thread.  Fix that by moving the SetThreadName call right in front of the
thread function call.

Signed-off-by: Corinna Vinschen <corinna@vinschen.de>

winsup/cygwin/cygthread.cc

@@ -87,6 +87,7 @@ cygthread::stub (VOID *arg)
 #endif
       else
 	{
+	  SetThreadName (info->id, info->__name);
 	  info->callfunc (false);
 
 	  HANDLE notify = info->notify_detached;
@@ -128,6 +129,7 @@ cygthread::simplestub (VOID *arg)
   _my_tls._ctinfo = info;
   info->stack_ptr = &arg;
   HANDLE notify = info->notify_detached;
+  SetThreadName (info->id, info->__name);
   info->callfunc (true);
   if (notify)
      SetEvent (notify);
@@ -213,8 +215,6 @@ cygthread::create ()
 			    this, 0, &id);
       if (!htobe)
 	api_fatal ("CreateThread failed for %s - %p<%y>, %E", __name, h, id);
-      else
-	SetThreadName (GetThreadId (htobe), __name);
       thread_printf ("created name '%s', thread %p, id %y", __name, h, id);
 #ifdef DEBUGGING
       terminated = false;

winsup/cygwin/release/2.12.0

@@ -77,3 +77,5 @@ Bug Fixes
 
 - Fix WEOF handling in wctype functions.
   Addresses: https://cygwin.com/ml/cygwin/2018-12/msg00173.html
+
+- Fix thread names in GDB when cygthreads get reused.