Enable IPv4PacketInfo and Ipv6PacketInfo on more OSes.

This was an oversight from PR #1002

Author: asomers

src/sys/socket/mod.rs

@@ -543,15 +543,19 @@ pub enum ControlMessageOwned {
         target_os = "android",
         target_os = "ios",
         target_os = "linux",
-        target_os = "macos"
+        target_os = "macos",
+        target_os = "netbsd",
     ))]
     Ipv4PacketInfo(libc::in_pktinfo),
     #[cfg(any(
         target_os = "android",
+        target_os = "dragonfly",
         target_os = "freebsd",
         target_os = "ios",
         target_os = "linux",
-        target_os = "macos"
+        target_os = "macos",
+        target_os = "openbsd",
+        target_os = "netbsd",
     ))]
     Ipv6PacketInfo(libc::in6_pktinfo),
     #[cfg(any(
@@ -625,7 +629,8 @@ impl ControlMessageOwned {
                 target_os = "android",
                 target_os = "ios",
                 target_os = "linux",
-                target_os = "macos"
+                target_os = "macos",
+                target_os = "netbsd",
             ))]
             (libc::IPPROTO_IP, libc::IP_PKTINFO) => {
                 let info = ptr::read_unaligned(p as *const libc::in_pktinfo);