Kernel: Add definition for MSB_EOR

None of the protocols we support at the moment use this, but it makes
boost happy.

Author: gunnarbeutner

Kernel/API/POSIX/sys/socket.h

@@ -61,6 +61,7 @@ extern "C" {
 #define MSG_WAITALL 0x20
 #define MSG_DONTWAIT 0x40
 #define MSG_NOSIGNAL 0x80
+#define MSG_EOR 0x100
 
 typedef uint16_t sa_family_t;