Prefer thr_yield over sched_yield for Solaris

configure.in

@@ -1484,11 +1484,12 @@ dnl			[ol_cv_pthread_lpthread_lexc])
 
 			dnl All POSIX Thread (final) implementations should have
 			dnl sched_yield instead of pthread yield.
-			dnl check for both
-			AC_CHECK_FUNCS(sched_yield pthread_yield)
+			dnl check for both, and thr_yield for Solaris
+			AC_CHECK_FUNCS(sched_yield pthread_yield thr_yield)
 
 			if test $ac_cv_func_sched_yield = no -a \
-				$ac_cv_func_pthread_yield = no ; then
+				$ac_cv_func_pthread_yield = no -a \
+				$ac_cv_func_thr_yield = no ; then
 				dnl Digital UNIX has sched_yield() in -lrt
 				AC_CHECK_LIB(rt, sched_yield,
 					[LTHREAD_LIBS="$LTHREAD_LIBS -lrt"
@@ -1497,12 +1498,6 @@ dnl			[ol_cv_pthread_lpthread_lexc])
 					ac_cv_func_sched_yield=yes],
 					[ac_cv_func_sched_yield=no])
 			fi
-			if test $ac_cv_func_sched_yield = no -a \
-				$ac_cv_func_pthread_yield = no ; then
-				dnl Solaris has sched_yield() stub in -lposix4
-				dnl but we'll use thr_yield instead.
-				AC_CHECK_FUNCS(thr_yield)
-			fi
 			if test $ac_cv_func_sched_yield = no -a \
 				$ac_cv_func_pthread_yield = no -a \
 				"$ac_cv_func_thr_yield" = no ; then

libraries/libldap_r/thr_posix.c

@@ -179,16 +179,16 @@ ldap_pvt_thread_kill( ldap_pvt_thread_t thread, int signo )
 int 
 ldap_pvt_thread_yield( void )
 {
-#if HAVE_PTHREADS == 10
+#if HAVE_THR_YIELD
+	return thr_yield();
+
+#elif HAVE_PTHREADS == 10
 	return sched_yield();
 
 #elif defined(_POSIX_THREAD_IS_GNU_PTH)
 	sched_yield();
 	return 0;
 
-#elif HAVE_THR_YIELD
-	return thr_yield();
-
 #elif HAVE_PTHREADS == 6
 	pthread_yield(NULL);
 	return 0;