Add a test for fchdir().
This is part of SF feature #536796.
diff --git a/configure.in b/configure.in
index d3211a0..7aef29a 100644
--- a/configure.in
+++ b/configure.in
@@ -1580,7 +1580,7 @@
# 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 \