Create _Py_wchar2char() function, reverse of _Py_char2wchar()

 * Use _Py_wchar2char() in _wstat() and _Py_wfopen()
 * Document _Py_char2wchar()
diff --git a/Include/Python.h b/Include/Python.h
index 1def75b..d5ac13e 100644
--- a/Include/Python.h
+++ b/Include/Python.h
@@ -126,12 +126,15 @@
 #ifdef __cplusplus
 extern "C" {
 #endif
+
 /* _Py_Mangle is defined in compile.c */
 PyAPI_FUNC(PyObject*) _Py_Mangle(PyObject *p, PyObject *name);
 
 /* These functions live in main.c */
 PyAPI_FUNC(wchar_t *) _Py_char2wchar(char *);
+PyAPI_FUNC(char*) _Py_wchar2char(const wchar_t *text);
 PyAPI_FUNC(FILE *) _Py_wfopen(const wchar_t *path, const wchar_t *mode);
+
 #ifdef __cplusplus
 }
 #endif