Patch #1272, by Christian Heimes and Alexandre Vassalotti.
Changes to make __file__ a proper Unicode object, using the default
filesystem encoding.
This is a bit tricky because the default filesystem encoding isn't
set by the time we import the first modules; at that point we fudge
things a bit.  This is okay since __file__ isn't really used much
except for error reporting.
Tested on OSX and Linux only so far.
diff --git a/Modules/pyexpat.c b/Modules/pyexpat.c
index 6cfb8ec..ae6f143 100644
--- a/Modules/pyexpat.c
+++ b/Modules/pyexpat.c
@@ -232,13 +232,13 @@
         code = PyString_FromString("");
         if (code == NULL)
             goto failed;
-        name = PyString_FromString(func_name);
+        name = PyUnicode_FromString(func_name);
         if (name == NULL)
             goto failed;
         nulltuple = PyTuple_New(0);
         if (nulltuple == NULL)
             goto failed;
-        filename = PyString_FromString(__FILE__);
+        filename = PyUnicode_DecodeFSDefault(__FILE__);
         handler_info[slot].tb_code =
             PyCode_New(0,		/* argcount */
                        0,       /* kwonlyargcount */