Exclude redox from cmsg test

Author: JohnTitor

libc-test/build.rs

@@ -8,7 +8,7 @@ use std::env;
 fn do_cc() {
     let target = env::var("TARGET").unwrap();
     if cfg!(unix) {
-        let exclude = ["wasi"];
+        let exclude = ["redox", "wasi"];
         if !exclude.iter().any(|x| target.contains(x)) {
             let mut cmsg = cc::Build::new();