Fix the ImportWarning regarding __spec__ and __package__ being None (GH-16003)

(cherry picked from commit 6e1a30b15e)

Co-authored-by: Xtreak <tir.karthi@gmail.com>

Lib/test/test_builtin.py

@@ -161,6 +161,7 @@ class BuiltinTest(unittest.TestCase):
         self.assertRaises(ValueError, __import__, '')
         self.assertRaises(TypeError, __import__, 'sys', name='sys')
         # Relative import outside of a package with no __package__ or __spec__ (bpo-37409).
+        with self.assertWarns(ImportWarning):
             self.assertRaises(ImportError, __import__, '',
                               {'__package__': None, '__spec__': None, '__name__': '__main__'},
                               locals={}, fromlist=('foo',), level=1)