Fix the build on s390x

.travis.yml

@@ -33,7 +33,7 @@ matrix:
     # build documentation
     - os: linux
       env: TARGET=x86_64-unknown-linux-gnu
-      rust: stable
+      rust: nightly
       script: sh ci/dox.sh
 
     # stable compat

src/lib.rs

@@ -33,6 +33,9 @@
 #![cfg_attr(all(target_os = "linux", target_arch = "aarch64"), doc(
     html_root_url = "https://doc.rust-lang.org/libc/aarch64-unknown-linux-gnu"
 ))]
+#![cfg_attr(all(target_os = "linux", target_arch = "s390x"), doc(
+    html_root_url = "https://doc.rust-lang.org/libc/s390x-unknown-linux-gnu"
+))]
 #![cfg_attr(all(target_os = "linux", target_env = "musl"), doc(
     html_root_url = "https://doc.rust-lang.org/libc/x86_64-unknown-linux-musl"
 ))]

src/unix/notbsd/linux/s390x.rs

@@ -233,6 +233,20 @@ s! {
         pub uc_mcontext: mcontext_t,
         pub uc_sigmask: ::sigset_t,
     }
+
+    pub struct msqid_ds {
+        pub msg_perm: ::ipc_perm,
+        pub msg_stime: ::time_t,
+        pub msg_rtime: ::time_t,
+        pub msg_ctime: ::time_t,
+        __msg_cbytes: ::c_ulong,
+        pub msg_qnum: ::msgqnum_t,
+        pub msg_qbytes: ::msglen_t,
+        pub msg_lspid: ::pid_t,
+        pub msg_lrpid: ::pid_t,
+        __glibc_reserved4: ::c_ulong,
+        __glibc_reserved5: ::c_ulong,
+    }
 }
 
 pub const POSIX_FADV_DONTNEED: ::c_int = 6;