add linux extension POLLRDHUP to poll.h

the POLL prefix is in the reserved namespace for poll.h, so no feature
test macro checks are needed.

1 files changed, 1 insertions, 0 deletions

diff --git a/include/poll.h b/include/poll.h
index f0e68b2f..9a785307 100644
--- a/include/poll.h
+++ b/include/poll.h
@@ -18,6 +18,7 @@ extern "C" {
 #define POLLWRNORM 0x100
 #define POLLWRBAND 0x200
 #define POLLMSG    0x400
+#define POLLRDHUP  0x2000
 
 typedef unsigned long nfds_t;