fixup! Add bindings for iconv calls

Link with iconv on macOS and iOS.

Author: Minoru

src/unix/mod.rs

@@ -344,8 +344,12 @@ cfg_if! {
         #[link(name = "m")]
         extern {}
     } else if #[cfg(any(target_os = "macos",
-                        target_os = "ios",
-                        target_os = "android",
+                        target_os = "ios"))] {
+        #[link(name = "c")]
+        #[link(name = "m")]
+        #[link(name = "iconv")]
+        extern {}
+    } else if #[cfg(any(target_os = "android",
                         target_os = "openbsd"))] {
         #[link(name = "c")]
         #[link(name = "m")]