Auto merge of #29083 - petrochenkov:stability3, r=alexcrichton

What this patch does:
- Stability annotations are now based on "exported items" supplied by rustc_privacy and not "public items". Exported items are as accessible for external crates as directly public items and should be annotated with stability attributes.
- Trait impls require annotations now.
- Reexports require annotations now.
- Crates themselves didn't require annotations, now they do.
- Exported macros are annotated now, but these annotations are not used yet.
- Some useless annotations are detected and result in errors
- Finally, some small bugs are fixed - deprecation propagates from stable deprecated parents, items in blocks are traversed correctly (fixes https://github.com/rust-lang/rust/issues/29034) + some code cleanup.

1 files changed, 2 insertions, 0 deletions

diff --git a/src/libstd/sys/unix/time.rs b/src/libstd/sys/unix/time.rs
index 5192f01269d..5b60b821c34 100644
--- a/src/libstd/sys/unix/time.rs
+++ b/src/libstd/sys/unix/time.rs
@@ -47,6 +47,7 @@ mod inner {
         }
     }
 
+    #[unstable(feature = "libstd_sys_internals", issue = "0")]
     impl<'a> Sub for &'a SteadyTime {
         type Output = Duration;
 
@@ -98,6 +99,7 @@ mod inner {
         }
     }
 
+    #[unstable(feature = "libstd_sys_internals", issue = "0")]
     impl<'a> Sub for &'a SteadyTime {
         type Output = Duration;