Mitigate #19412: restore test skips for --without-doc-strings

Lib/test/support/__init__.py

@@ -1703,7 +1703,12 @@ def run_unittest(*classes):
 def _check_docstrings():
     """Just used to check if docstrings are enabled"""
 
-HAVE_DOCSTRINGS = (_check_docstrings.__doc__ is not None)
+MISSING_C_DOCSTRINGS = (check_impl_detail() and
+                        sys.platform != 'win32' and
+                        not sysconfig.get_config_var('WITH_DOC_STRINGS'))
+
+HAVE_DOCSTRINGS = (_check_docstrings.__doc__ is not None and
+                   not MISSING_C_DOCSTRINGS)
 
 requires_docstrings = unittest.skipUnless(HAVE_DOCSTRINGS,
                                           "test requires docstrings")