add early_break for extend_layers

benches/future_children.rs

@@ -11,6 +11,7 @@ fn extend_layers_test(depth: usize) {
         start_pruning_at_minus: 4,
         top_k_children: 2,
         up_to_mod: 4,
+        max_arena_size: 10_000_000,
     };
     let mut fut = FutureMoves::new(Piece::Black, config);
     fut.set_root_from_board(Board::new().starting_pos());