SCTP support for FreeBSD, NetBSD

Notification and log `union` types are exposed as partially-opaque structs
for now, until libc targets a version of Rust which supports unions.

Author: jack-pappas

libc-test/build.rs

@@ -244,9 +244,12 @@ fn main() {
     if linux || android {
         cfg.header("sys/fsuid.h");
 
-        // DCCP support
         if !uclibc && !musl && !emscripten {
+            // DCCP support
             cfg.header("linux/dccp.h");
+
+            // SCTP support
+            //cfg.header("netinet/sctp.h");
         }
     }
 
@@ -258,6 +261,9 @@ fn main() {
         cfg.header("sys/ipc.h");
         cfg.header("sys/msg.h");
         cfg.header("sys/shm.h");
+
+        // SCTP support
+        cfg.header("netinet/sctp.h");
     }
 
     if netbsd {
@@ -267,6 +273,9 @@ fn main() {
 
         // DCCP support
         cfg.header("netinet/dccp.h");
+
+        // SCTP support
+        cfg.header("netinet/sctp.h");
     }
 
     if openbsd {