Issue #21741: Update 147 test modules to use test discovery.

I have compared output between pre- and post-patch runs of these tests
to make sure there's nothing missing and nothing broken, on both
Windows and Linux.  The only differences I found were actually tests
that were previously *not* run.

1 files changed, 2 insertions, 5 deletions

diff --git a/Lib/test/test_readline.py b/Lib/test/test_readline.py
index 23d6194..e2063b1 100644
--- a/Lib/test/test_readline.py
+++ b/Lib/test/test_readline.py
@@ -4,7 +4,7 @@ Very minimal unittests for parts of the readline module.
 import os
 import tempfile
 import unittest
-from test.support import run_unittest, import_module, unlink
+from test.support import import_module, unlink
 from test.script_helper import assert_python_ok
 
 # Skip tests if there is no readline module
@@ -97,8 +97,5 @@ class TestReadline(unittest.TestCase):
         self.assertEqual(stdout, b'')
 
 
-def test_main():
-    run_unittest(TestHistoryManipulation, TestReadline)
-
 if __name__ == "__main__":
-    test_main()
+    unittest.main()