merge with 3.3

diff --cc Lib/test/test_importlib/test_api.py
index ef6629a225489e00af5c90c1eb00d7d7fdc05def,3c3ba89d7596eed60eba1188a5777a22e86d1b1e..7acb4cea54d797302cc6795f8df33891bd4e9407
--- 1/Lib/test/test_importlib/test_api.py
--- 2/Lib/test/test_importlib/test_api.py
+++ b/Lib/test/test_importlib/test_api.py
@@@ -175,13 -176,23 +176,15 @@@ class FrozenImportlibTests(unittest.Tes
                                      machinery.FrozenImporter))
  
  
- def test_main():
-     from test.support import run_unittest
-     run_unittest(ImportModuleTests,
-                  FindLoaderTests,
-                  InvalidateCacheTests,
-                  FrozenImportlibTests)
+ class StartupTests(unittest.TestCase):
+ 
+     def test_everyone_has___loader__(self):
+         # Issue #17098: all modules should have __loader__ defined.
+         for name, module in sys.modules.items():
+             if isinstance(module, types.ModuleType):
+                 self.assertTrue(hasattr(module, '__loader__'),
+                         '{!r} lacks a __loader__ attribute'.format(name))
  
 -def test_main():
 -    from test.support import run_unittest
 -    run_unittest(ImportModuleTests,
 -                 FindLoaderTests,
 -                 InvalidateCacheTests,
 -                 FrozenImportlibTests,
 -                 StartupTests)
 -
  
  if __name__ == '__main__':
--    test_main()
++    unittest.main()