RecyclableCollections.Contains(T item) fixes to exceptions found by tests.

Recyclable.Collections/RecyclableList.cs

@@ -719,7 +719,7 @@ namespace Recyclable.Collections
 				}
 			}
 
-			return Array.IndexOf(memoryBlocksSpan[lastBlockIndex], item, 0, _nextItemIndex) >= 0;
+			return lastBlockIndex < memoryBlocksSpan.Length && Array.IndexOf(memoryBlocksSpan[lastBlockIndex], item, 0, _nextItemIndex) >= 0;
 		}
 
 		public void CopyTo(T[] array, int arrayIndex) => _memoryBlocks.CopyTo(0, _blockSize, _longCount, array, arrayIndex);