rollup merge of #23908: aturon/stab-more-stragglers

* The `io::Seek` trait.
* The `Iterator::{partition, unsip}` methods.
* The `Vec::into_boxed_slice` method.
* The `LinkedList::append` method.
* The `{or_insert, or_insert_with` methods in the `Entry` APIs.

r? @alexcrichton

1 files changed, 1 insertions, 0 deletions

diff --git a/src/libcollections/linked_list.rs b/src/libcollections/linked_list.rs
index 392dc7346c6..a65fc9b7f6a 100644
--- a/src/libcollections/linked_list.rs
+++ b/src/libcollections/linked_list.rs
@@ -248,6 +248,7 @@ impl<T> LinkedList<T> {
     /// }
     /// println!("{}", b.len()); // prints 0
     /// ```
+    #[stable(feature = "rust1", since = "1.0.0")]
     pub fn append(&mut self, other: &mut LinkedList<T>) {
         match self.list_tail.resolve() {
             None => {