Allow extern abi to be specified as "C++"
diff --git a/syntax/parse.rs b/syntax/parse.rs
index e07ee25..2258dd6 100644
--- a/syntax/parse.rs
+++ b/syntax/parse.rs
@@ -111,7 +111,7 @@
         }
     };
     match name.value().as_str() {
-        "C" => Ok(Lang::Cxx),
+        "C" | "C++" => Ok(Lang::Cxx),
         "Rust" => Ok(Lang::Rust),
         _ => Err(Error::new_spanned(abi, "unrecognized ABI")),
     }