Remove dart backend

test/dart_codegen/expect/collection/iterator.dart

-part of dart.collection;
- class HasNextIterator<E> {static const int _HAS_NEXT_AND_NEXT_IN_CURRENT = 0;
- static const int _NO_NEXT = 1;
- static const int _NOT_MOVED_YET = 2;
- Iterator _iterator;
- int _state = _NOT_MOVED_YET;
- HasNextIterator(this._iterator);
- bool get hasNext {
-  if (_state == _NOT_MOVED_YET) _move();
-   return _state == _HAS_NEXT_AND_NEXT_IN_CURRENT;
-  }
- E next() {
-  if (!hasNext) throw new StateError("No more elements");
-   assert (_state == _HAS_NEXT_AND_NEXT_IN_CURRENT); E result = DEVC$RT.cast(_iterator.current, dynamic, E, "CompositeCast", """line 33, column 16 of dart:collection/iterator.dart: """, _iterator.current is E, false);
-   _move();
-   return result;
-  }
- void _move() {
-  if (_iterator.moveNext()) {
-    _state = _HAS_NEXT_AND_NEXT_IN_CURRENT;
-    }
-   else {
-    _state = _NO_NEXT;
-    }
-  }
-}