[configure.ac] add tests for recvmsg and sendmsg.
[monitor_fdpass.c] add checks for HAVE_SENDMSG and HAVE_RECVMSG for
systems that HAVE_ACCRIGHTS_IN_MSGHDR but no recvmsg or sendmsg.
diff --git a/monitor_fdpass.c b/monitor_fdpass.c
index 0045977..5401ea4 100644
--- a/monitor_fdpass.c
+++ b/monitor_fdpass.c
@@ -34,7 +34,7 @@
void
mm_send_fd(int socket, int fd)
{
-#if defined(HAVE_ACCRIGHTS_IN_MSGHDR) || defined(HAVE_CONTROL_IN_MSGHDR)
+#if defined(HAVE_SENDMSG) && (defined(HAVE_ACCRIGHTS_IN_MSGHDR) || defined(HAVE_CONTROL_IN_MSGHDR))
struct msghdr msg;
struct iovec vec;
char ch = '\0';
@@ -78,7 +78,7 @@
int
mm_receive_fd(int socket)
{
-#if defined(HAVE_ACCRIGHTS_IN_MSGHDR) || defined(HAVE_CONTROL_IN_MSGHDR)
+#if defined(HAVE_RECVMSG) && (defined(HAVE_ACCRIGHTS_IN_MSGHDR) || defined(HAVE_CONTROL_IN_MSGHDR))
struct msghdr msg;
struct iovec vec;
char ch;