lit: remove python2-isms

[jbergstroem]

Summary

assert.assertItemEqual went away in Python 3. Seeing how lists
are ordered, comparing a list against each other should work just
as well.

[jbergstroem]

(adding last person who touched the code)

[modocache]

Looks good to me, thanks! Let me know if you'd like me to commit this code for you.

[jbergstroem]

In D31229#707251, @modocache wrote:

Looks good to me, thanks! Let me know if you'd like me to commit this code for you.

That'd be great. Thanks!

llvm/trunk/utils/lit/tests/unit/TestRunner.py

def test_tags(self):
         dne_tag_parser = self.get_parser(parsers, 'MY_DNE_TAG.')
         self.assertTrue(tag_parser.getValue())
         self.assertFalse(dne_tag_parser.getValue())
 
     def test_lists(self):
         parsers = self.make_parsers()
         self.parse_test(parsers)
         list_parser = self.get_parser(parsers, 'MY_LIST:')
-        self.assertItemsEqual(list_parser.getValue(),
+        self.assertEqual(list_parser.getValue(),
                               ['one', 'two', 'three', 'four'])
 
     def test_commands(self):
         parsers = self.make_parsers()
         self.parse_test(parsers)
         cmd_parser = self.get_parser(parsers, 'MY_RUN:')
         value = cmd_parser.getValue()
         self.assertEqual(len(value), 2)  # there are only two run lines
         self.assertEqual(value[0].strip(), 'baz')
         self.assertEqual(value[1].strip(), 'foo  bar')
 
     def test_custom(self):
         parsers = self.make_parsers()
         self.parse_test(parsers)
         custom_parser = self.get_parser(parsers, 'MY_CUSTOM:')
         value = custom_parser.getValue()
-        self.assertItemsEqual(value, ['a', 'b', 'c'])
+        self.assertEqual(value, ['a', 'b', 'c'])
 
     def test_bad_keywords(self):
         def custom_parse(line_number, line, output):
             return output
         
         try:
             IntegratedTestKeywordParser("TAG_NO_SUFFIX", ParserKind.TAG),
             self.fail("TAG_NO_SUFFIX failed to raise an exception")