Replace predicate find with simple find

src/DotRecast.Core/Collections/RcSortedQueue.cs

@@ -88,7 +88,7 @@ namespace DotRecast.Core.Collections
                 return false;
 
             //int idx = _items.BinarySearch(item, _comparer); // don't use this! Because reference types can be reused externally.
-            int idx = _items.FindLastIndex(x => item.Equals(x));
+            int idx = _items.LastIndexOf(item);
             if (0 > idx)
                 return false;