Downwards closure inference

test/dart_codegen/expect/collection/queue.dart

 part of dart.collection;
  abstract class Queue<E> implements Iterable<E>, EfficientLength {factory Queue() = ListQueue<E>;
  factory Queue.from(Iterable elements) = ListQueue<E>.from;
  E removeFirst();
  E removeLast();
  void addFirst(E value);
  void addLast(E value);
  void add(E value);
  bool remove(Object object);
  void addAll(Iterable<E> iterable);
@@ skipping 476 matching lines @@
  int _position;
  E _current;
  _ListQueueIterator(ListQueue queue) : _queue = queue, _end = queue._tail, _modificationCount = queue._modificationCount, _position = queue._head;
  E get current => _current;
  bool moveNext() {
 _queue._checkModification(_modificationCount);
  if (_position == _end) {
 _current = null;
  return false;
 }
- _current = ((__x17) => DEVC$RT.cast(__x17, dynamic, E, "CompositeCast", """line 738, column 16 of dart:collection/queue.dart: """, __x17 is E, false))(_queue._table[_position]);
+ _current = ((__x11) => DEVC$RT.cast(__x11, dynamic, E, "CompositeCast", """line 738, column 16 of dart:collection/queue.dart: """, __x11 is E, false))(_queue._table[_position]);
  _position = (_position + 1) & (_queue._table.length - 1);
  return true;
 }
 }