Issue #8622: Add PYTHONFSENCODING environment variable to override the
filesystem encoding.

initfsencoding() displays also a better error message if get_codeset() failed.
diff --git a/Doc/whatsnew/3.2.rst b/Doc/whatsnew/3.2.rst
index a2b7af4..1799b70 100644
--- a/Doc/whatsnew/3.2.rst
+++ b/Doc/whatsnew/3.2.rst
@@ -232,6 +232,15 @@
 
 * Stub
 
+
+Unicode
+=======
+
+The filesystem encoding can be specified by setting the
+:envvar:`PYTHONFSENCODING` environment variable before running the intepreter.
+The value should be a string in the form ``<encoding>``, e.g. ``utf-8``.
+
+
 IDLE
 ====