Fix bad default value for SubListIterable.toList.

sdk/lib/internal/iterable.dart

Index: sdk/lib/internal/iterable.dart
diff --git a/sdk/lib/internal/iterable.dart b/sdk/lib/internal/iterable.dart
index 78cebced560803c219dfc51a76f37b55fde7eab8..58301a7ca1cdfb1441491e738b545e073fe7f241 100644
--- a/sdk/lib/internal/iterable.dart
+++ b/sdk/lib/internal/iterable.dart
@@ -294,7 +294,7 @@ class SubListIterable<E> extends ListIterable<E> {
     }
   }
 
-  List<E> toList({bool growable: false}) {
+  List<E> toList({bool growable: true}) {
     int start = _start;
     int end = _iterable.length;
     if (_endOrLength != null && _endOrLength < end) end = _endOrLength;