Improvements to feature staging

This gets rid of the 'experimental' level, removes the non-staged_api
case (i.e. stability levels for out-of-tree crates), and lets the
staged_api attributes use 'unstable' and 'deprecated' lints.

This makes the transition period to the full feature staging design
a bit nicer.

1 files changed, 1 insertions, 1 deletions

diff --git a/src/libcoretest/cell.rs b/src/libcoretest/cell.rs
index 86f34ecd15e..a808593ffbd 100644
--- a/src/libcoretest/cell.rs
+++ b/src/libcoretest/cell.rs
@@ -114,7 +114,7 @@ fn discard_doesnt_unborrow() {
 }
 
 #[test]
-#[allow(experimental)]
+#[allow(unstable)]
 fn clone_ref_updates_flag() {
     let x = RefCell::new(0i);
     {