bpo-43288: Fix bug in test_importlib test. (GH-24612)

Lib/test/test_importlib/fixtures.py

@@ -5,6 +5,7 @@ import pathlib
 import tempfile
 import textwrap
 import contextlib
+import unittest
 
 from test.support.os_helper import FS_NONASCII
 from typing import Dict, Union
@@ -219,6 +220,9 @@ class LocalPackage:
         self.fixtures.enter_context(tempdir_as_cwd())
         build_files(self.files)
 
+    def skip(self, reason):
+        raise unittest.SkipTest(reason)
+
 
 def build_files(file_defs, prefix=pathlib.Path()):
     """Build a set of files/directories, as described by the

Misc/NEWS.d/next/Tests/2021-02-21-11-11-53.bpo-43288.LfTvL-.rst

@@ -0,0 +1,2 @@
+Fix test_importlib to correctly skip Unicode file tests if the fileystem
+does not support them.