allow compilation on haiku beta 4

Author: superboum

src/socket.rs

@@ -1442,6 +1442,7 @@ impl Socket {
         target_os = "openbsd",
         target_os = "redox",
         target_os = "solaris",
+        target_os = "haiku",
     )))]
     pub fn set_recv_tos(&self, recv_tos: bool) -> io::Result<()> {
         unsafe {
@@ -1467,6 +1468,7 @@ impl Socket {
         target_os = "openbsd",
         target_os = "redox",
         target_os = "solaris",
+        target_os = "haiku",
     )))]
     pub fn recv_tos(&self) -> io::Result<bool> {
         unsafe {
@@ -1679,6 +1681,7 @@ impl Socket {
         target_os = "openbsd",
         target_os = "redox",
         target_os = "solaris",
+        target_os = "haiku",
     )))]
     pub fn recv_tclass_v6(&self) -> io::Result<bool> {
         unsafe {
@@ -1700,6 +1703,7 @@ impl Socket {
         target_os = "openbsd",
         target_os = "redox",
         target_os = "solaris",
+        target_os = "haiku",
     )))]
     pub fn set_recv_tclass_v6(&self, recv_tclass: bool) -> io::Result<()> {
         unsafe {

src/sys/unix.rs

@@ -84,6 +84,7 @@ pub(crate) use libc::{MSG_TRUNC, SO_OOBINLINE};
     target_os = "openbsd",
     target_os = "redox",
     target_os = "solaris",
+    target_os = "haiku",
 )))]
 pub(crate) use libc::IPV6_RECVTCLASS;
 #[cfg(all(feature = "all", not(target_os = "redox")))]
@@ -96,6 +97,7 @@ pub(crate) use libc::IP_HDRINCL;
     target_os = "openbsd",
     target_os = "redox",
     target_os = "solaris",
+    target_os = "haiku",
 )))]
 pub(crate) use libc::IP_RECVTOS;
 #[cfg(not(any(