bpo-38493: Add os.CLD_KILLED and os.CLD_STOPPED. (GH-16821)

diff --git a/Lib/test/test_posix.py b/Lib/test/test_posix.py
index 9bdd284..17e4ded2 100644
--- a/Lib/test/test_posix.py
+++ b/Lib/test/test_posix.py
@@ -1226,6 +1226,16 @@
         finally:
             posix.close(f)
 
+    @unittest.skipUnless(hasattr(signal, 'SIGCHLD'), 'CLD_XXXX be placed in si_code for a SIGCHLD signal')
+    @unittest.skipUnless(hasattr(os, 'waitid_result'), "test needs os.waitid_result")
+    def test_cld_xxxx_constants(self):
+        os.CLD_EXITED
+        os.CLD_KILLED
+        os.CLD_DUMPED
+        os.CLD_TRAPPED
+        os.CLD_STOPPED
+        os.CLD_CONTINUED
+
     @unittest.skipUnless(os.symlink in os.supports_dir_fd, "test needs dir_fd support in os.symlink()")
     def test_symlink_dir_fd(self):
         f = posix.open(posix.getcwd(), posix.O_RDONLY)