Rename utf8b error handler to surrogateescape.
diff --git a/Objects/unicodeobject.c b/Objects/unicodeobject.c
index 3740892..3bd1efd 100644
--- a/Objects/unicodeobject.c
+++ b/Objects/unicodeobject.c
@@ -1549,7 +1549,7 @@
             return 0;
         output = PyUnicode_AsEncodedObject(arg, 
                                            Py_FileSystemDefaultEncoding,
-                                           "utf8b");
+                                           "surrogateescape");
         Py_DECREF(arg);
         if (!output)
             return 0;