Add a test for fchdir().
This is part of SF feature #536796.
diff --git a/pyconfig.h.in b/pyconfig.h.in
index 0bd5485..cb8b1b5 100644
--- a/pyconfig.h.in
+++ b/pyconfig.h.in
@@ -86,6 +86,9 @@
 /* Define to 1 if you have the `execv' function. */
 #undef HAVE_EXECV
 
+/* Define to 1 if you have the `fchdir' function. */
+#undef HAVE_FCHDIR
+
 /* Define to 1 if you have the <fcntl.h> header file. */
 #undef HAVE_FCNTL_H