Take sys/vxworks/rwlock from sys/unix instead.

Author: m-ou-se

library/std/src/sys/vxworks/mod.rs

@@ -26,6 +26,7 @@ pub mod path;
 pub mod pipe;
 pub mod process;
 pub mod rand;
+#[path = "../unix/rwlock.rs"]
 pub mod rwlock;
 pub mod stack_overflow;
 pub mod stdio;