tests: backport an additional test case

Author: calebcartwright

src/attr.rs

@@ -2,7 +2,7 @@
 
 use rustc_ast::ast;
 use rustc_ast::attr::HasAttrs;
-use rustc_span::{symbol::sym, BytePos, Span, Symbol, DUMMY_SP};
+use rustc_span::{symbol::sym, Span, Symbol};
 
 use self::doc_comment::DocCommentFormatter;
 use crate::comment::{contains_comment, rewrite_doc_comment, CommentStyle};

tests/target/issue_4545.rs

@@ -0,0 +1,5 @@
+#[derive(Debug, Foo<T>)]
+enum Bar {}
+
+#[derive(Debug, , Default)]
+struct Struct(i32);