Library changes for Apple WatchOS

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

@@ -86,6 +86,7 @@ pub unsafe fn init(argc: isize, argv: *const *const u8) {
             // The poll on Darwin doesn't set POLLNVAL for closed fds.
             target_os = "macos",
             target_os = "ios",
+            target_os = "watchos",
             target_os = "redox",
             target_os = "l4re",
             target_os = "horizon",
@@ -329,7 +330,7 @@ cfg_if::cfg_if! {
         // See #41582 and https://blog.achernya.com/2013/03/os-x-has-silly-libsystem.html
         #[link(name = "resolv")]
         extern "C" {}
-    } else if #[cfg(target_os = "ios")] {
+    } else if #[cfg(any(target_os = "ios", target_os = "watchos"))] {
         #[link(name = "System")]
         #[link(name = "objc")]
         #[link(name = "Security", kind = "framework")]