Rollup merge of rust-lang#67436 - NieDzejkob:todo-stabilization-fix, r=alexcrichton

Correct the todo! stabilization version

None

Author: Mark-Simulacrum

src/libcore/macros/mod.rs

@@ -686,7 +686,7 @@ macro_rules! unimplemented {
 /// }
 /// ```
 #[macro_export]
-#[stable(feature = "todo_macro", since = "1.39.0")]
+#[stable(feature = "todo_macro", since = "1.40.0")]
 macro_rules! todo {
     () => (panic!("not yet implemented"));
     ($($arg:tt)+) => (panic!("not yet implemented: {}", $crate::format_args!($($arg)+)));

src/libstd/lib.rs

@@ -524,8 +524,8 @@ pub use core::{
     unreachable,
     write,
     writeln,
-    // Unstable
     todo,
+    // Unstable
     matches,
 };