8332154: Memory leak in SynchronousQueue

Reviewed-by: alanb

src/java.base/share/classes/java/util/concurrent/SynchronousQueue.java

@@ -194,6 +194,8 @@ public class SynchronousQueue<E> extends AbstractQueue<E>
                     if ((m = s.await(e, ns, this,  // spin if (nearly) empty
                                      p == null || p.waiter == null)) == e)
                         unspliceLifo(s);           // cancelled
+                    else if (m != null)
+                        s.selfLinkItem();
                     break;
                 }
             }