bpo-31583: Fix 2to3 for using with --add-suffix option (GH-3758) (#6528)

(cherry picked from commit e3a523a0)
Co-authored-by: Denis Osipov <osipov_d@list.ru>

Lib/lib2to3/main.py

@@ -80,7 +80,7 @@ class StdoutRefactoringTool(refactor.MultiprocessRefactoringTool):
             filename += self._append_suffix
         if orig_filename != filename:
             output_dir = os.path.dirname(filename)
-            if not os.path.isdir(output_dir):
+            if not os.path.isdir(output_dir) and output_dir:
                 os.makedirs(output_dir)
             self.log_message('Writing converted %s to %s.', orig_filename,
                              filename)

Misc/NEWS.d/next/Tools-Demos/2017-09-26-10-11-21.bpo-31583.TM90_H.rst

+Fix 2to3 for using with --add-suffix option but without --output-dir
+option for relative path to files in current directory.