Stabilize thread::is_finished

Author: workingjubilee

library/std/src/thread/mod.rs

@@ -1471,7 +1471,7 @@ impl<T> JoinHandle<T> {
     ///
     /// This function does not block. To block while waiting on the thread to finish,
     /// use [`join`][Self::join].
-    #[unstable(feature = "thread_is_running", issue = "90470")]
+    #[stable(feature = "thread_is_running", since = "1.61.0")]
     pub fn is_finished(&self) -> bool {
         Arc::strong_count(&self.0.packet) == 1
     }

library/std/src/thread/scoped.rs

@@ -316,7 +316,7 @@ impl<'scope, T> ScopedJoinHandle<'scope, T> {
     ///
     /// This function does not block. To block while waiting on the thread to finish,
     /// use [`join`][Self::join].
-    #[unstable(feature = "thread_is_running", issue = "90470")]
+    #[stable(feature = "thread_is_running", since = "1.61.0")]
     pub fn is_finished(&self) -> bool {
         Arc::strong_count(&self.0.packet) == 1
     }