Fix span placement on extern functions
diff --git a/syntax/mod.rs b/syntax/mod.rs
index 12904c3..4dd18ea 100644
--- a/syntax/mod.rs
+++ b/syntax/mod.rs
@@ -113,6 +113,7 @@
     pub lang: Lang,
     pub doc: Doc,
     pub attrs: OtherAttrs,
+    pub visibility: Token![pub],
     pub name: Pair,
     pub sig: Signature,
     pub semi_token: Token![;],