Issue #12469: fix signal order check of test_signal

When signals are unblocked, pending signal ared delivered in the reverse order
of their number (also on Linux, not only on FreeBSD 6).

Don't sort signals by their number if signals were not blocked (test_signum).

Lib/test/test_signal.py

@@ -240,10 +240,6 @@ class WakeupSignalTests(unittest.TestCase):
         def check_signum(signals):
             data = os.read(read, len(signals)+1)
             raised = struct.unpack('%uB' % len(data), data)
-            if sys.platform == 'freebsd6':
-                # when signals are unblocked, FreeBSD 6 delivers signals in the
-                # reverse order of their number
-                signals = tuple(sorted(signals, reverse=False))
             if raised != signals:
                 raise Exception("%r != %r" % (raised, signals))
 
@@ -323,6 +319,11 @@ class WakeupSignalTests(unittest.TestCase):
     @unittest.skipUnless(hasattr(signal, 'pthread_sigmask'),
                          'need signal.pthread_sigmask()')
     def test_pending(self):
+        signals = (signal.SIGUSR1, signal.SIGUSR2)
+        # when signals are unblocked, pending signal ared delivered in the
+        # reverse order of their number
+        signals = tuple(sorted(signals, reverse=True))
+
         self.check_wakeup("""def test():
             signum1 = signal.SIGUSR1
             signum2 = signal.SIGUSR2
@@ -335,7 +336,7 @@ class WakeupSignalTests(unittest.TestCase):
             os.kill(os.getpid(), signum2)
             # Unblocking the 2 signals calls the C signal handler twice
             signal.pthread_sigmask(signal.SIG_UNBLOCK, (signum1, signum2))
-        """,  signal.SIGUSR1, signal.SIGUSR2)
+        """,  *signals)
 
 
 @unittest.skipIf(sys.platform == "win32", "Not valid on Windows")