Add C API test coverage (only test_long_fromunicodeobject)

- `CAPIFloatTest.test_fromstring` doesn't test for minus signs
- I can't find `complex` C API tests

Author: johnslavik

Lib/test/test_capi/test_long.py

@@ -143,7 +143,9 @@ def test_long_fromunicodeobject(self):
         self.assertEqual(fromunicodeobject('0xcafe', 0), 0xcafe)
         self.assertRaises(ValueError, fromunicodeobject, 'cafe', 0)
         self.assertEqual(fromunicodeobject('-123', 10), -123)
+        self.assertEqual(fromunicodeobject('\N{MINUS SIGN}123', 10), -123)
         self.assertEqual(fromunicodeobject(' -123 ', 10), -123)
+        self.assertEqual(fromunicodeobject(' \N{MINUS SIGN}123 ', 10), -123)
         self.assertEqual(fromunicodeobject('1_23', 10), 123)
         self.assertRaises(ValueError, fromunicodeobject, '- 123', 10)
         self.assertRaises(ValueError, fromunicodeobject, '', 10)