Add a test for fchdir().

This is part of SF feature #536796.

configure

 #! /bin/sh
-# From configure.in Revision: 1.307 .
+# From configure.in Revision: 1.309 .
 # Guess values for system-dependent variables and create Makefiles.
 # Generated by GNU Autoconf 2.53.
 #
@@ -11268,10 +11268,11 @@ echo "${ECHO_T}MACHDEP_OBJS" >&6
 
 
 
+
 
 
 for ac_func in alarm chown chroot clock confstr ctermid ctermid_r execv \
- flock fork fsync fdatasync fpathconf ftime ftruncate \
+ fchdir flock fork fsync fdatasync fpathconf ftime ftruncate \
  gai_strerror getgroups getlogin getpeername getpid getpwent getwd \
  hstrerror inet_pton kill killpg link lstat mkfifo mknod mktime mremap \
  nice pathconf pause plock poll pthread_init \

configure.in

@@ -1580,7 +1580,7 @@ AC_MSG_RESULT(MACHDEP_OBJS)
 
 # checks for library functions
 AC_CHECK_FUNCS(alarm chown chroot clock confstr ctermid ctermid_r execv \
- flock fork fsync fdatasync fpathconf ftime ftruncate \
+ fchdir flock fork fsync fdatasync fpathconf ftime ftruncate \
  gai_strerror getgroups getlogin getpeername getpid getpwent getwd \
  hstrerror inet_pton kill killpg link lstat mkfifo mknod mktime mremap \
  nice pathconf pause plock poll pthread_init \

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