Make Barrier RefUnwindSafe again

This commit manually implements `RefUnwindSafe` for
`std::sync::Barrier` to fix 146087. This is a fix for a regression
indroduced by https://github.com/rust-lang/rust/commit/e95db591a4550e28ad92660b753ad85b89271882

1 files changed, 10 insertions, 0 deletions

diff --git a/library/std/tests/sync/barrier.rs b/library/std/tests/sync/barrier.rs
index 8aefff9d507..cc9ee322c6c 100644
--- a/library/std/tests/sync/barrier.rs
+++ b/library/std/tests/sync/barrier.rs
@@ -1,3 +1,4 @@
+use std::panic::RefUnwindSafe;
 use std::sync::mpsc::{TryRecvError, channel};
 use std::sync::{Arc, Barrier};
 use std::thread;
@@ -33,3 +34,12 @@ fn test_barrier() {
     }
     assert!(leader_found);
 }
+
+#[expect(dead_code, reason = "this is essentially a compile pass test")]
+fn check_barrier_is_ref_unwind_safe() {
+    let barrier = Arc::new(Barrier::new(10));
+
+    fn check<T: RefUnwindSafe>(_: T) {}
+
+    check(barrier);
+}