ast: Add span to Extern

Author: aDotInTheVoid

src/items.rs

@@ -148,7 +148,7 @@ impl<'a> Item<'a> {
         Item {
             unsafety: fm.unsafety,
             abi: format_extern(
-                ast::Extern::from_abi(fm.abi),
+                ast::Extern::from_abi(fm.abi, DUMMY_SP),
                 config.force_explicit_abi(),
                 true,
             ),

src/utils.rs

@@ -138,8 +138,8 @@ pub(crate) fn format_extern(
 ) -> Cow<'static, str> {
     let abi = match ext {
         ast::Extern::None => "Rust".to_owned(),
-        ast::Extern::Implicit => "C".to_owned(),
-        ast::Extern::Explicit(abi) => abi.symbol_unescaped.to_string(),
+        ast::Extern::Implicit(_) => "C".to_owned(),
+        ast::Extern::Explicit(abi, _) => abi.symbol_unescaped.to_string(),
     };
 
     if abi == "Rust" && !is_mod {