mark format_args_nl! as #[doc(hidden)]

Author: cyrgani

library/core/src/macros/mod.rs

@@ -1017,6 +1017,7 @@ pub(crate) mod builtin {
     )]
     #[allow_internal_unstable(fmt_internals)]
     #[rustc_builtin_macro]
+    #[doc(hidden)]
     #[macro_export]
     macro_rules! format_args_nl {
         ($fmt:expr) => {{ /* compiler built-in */ }};

src/librustdoc/html/highlight.rs

@@ -578,7 +578,7 @@ pub(super) fn write_code(
 }
 
 fn write_footer(out: &mut String, playground_button: Option<&str>) {
-    write_str(out, format_args_nl!("</code></pre>{}</div>", playground_button.unwrap_or_default()));
+    write_str(out, format_args!("</code></pre>{}</div>\n", playground_button.unwrap_or_default()));
 }
 
 /// How a span of text is classified. Mostly corresponds to token kinds.

src/librustdoc/lib.rs

@@ -10,7 +10,6 @@
 #![feature(box_patterns)]
 #![feature(debug_closure_helpers)]
 #![feature(file_buffered)]
-#![feature(format_args_nl)]
 #![feature(if_let_guard)]
 #![feature(iter_advance_by)]
 #![feature(iter_intersperse)]