bpo-40275: Use new test.support helper submodules in tests (GH-21317)

diff --git a/Lib/test/test_sysconfig.py b/Lib/test/test_sysconfig.py
index 44e44bf..d07d28d 100644
--- a/Lib/test/test_sysconfig.py
+++ b/Lib/test/test_sysconfig.py
@@ -5,9 +5,11 @@
 import shutil
 from copy import copy
 
-from test.support import (import_module, TESTFN, unlink, check_warnings,
-                          captured_stdout, skip_unless_symlink, change_cwd,
-                          PythonSymlink)
+from test.support import (captured_stdout, PythonSymlink)
+from test.support.import_helper import import_module
+from test.support.os_helper import (TESTFN, unlink, skip_unless_symlink,
+                                    change_cwd)
+from test.support.warnings_helper import check_warnings
 
 import sysconfig
 from sysconfig import (get_paths, get_platform, get_config_vars,