fixes #202, check IndexExpression

test/dart_codegen/expect/_internal/list.dart

 part of dart._internal;
  abstract class FixedLengthListMixin<E> {void set length(int newLength) {
   throw new UnsupportedError("Cannot change the length of a fixed-length list");
   }
  void add(E value) {
   throw new UnsupportedError("Cannot add to a fixed-length list");
   }
  void insert(int index, E value) {
   throw new UnsupportedError("Cannot add to a fixed-length list");
   }
@@ skipping 91 matching lines @@
  class _ListIndicesIterable extends ListIterable<int> {List _backedList;
  _ListIndicesIterable(this._backedList);
  int get length => _backedList.length;
  int elementAt(int index) {
 RangeError.checkValidIndex(index, this);
  return index;
 }
 }
  class ListMapView<E> implements Map<int, E> {List<E> _values;
  ListMapView(this._values);
- E operator [](Object key) => containsKey(key) ? _values[key] : null;
+ E operator [](Object key) => containsKey(key) ? _values[DEVC$RT.cast(key, Object, int, "ImplicitCast", """line 251, column 59 of dart:_internal/list.dart: """, key is int, true)] : null;
  int get length => _values.length;
  Iterable<E> get values => new SubListIterable<E>(_values, 0, null);
  Iterable<int> get keys => new _ListIndicesIterable(_values);
  bool get isEmpty => _values.isEmpty;
  bool get isNotEmpty => _values.isNotEmpty;
  bool containsValue(Object value) => _values.contains(value);
  bool containsKey(Object key) => key is int && key >= 0 && key < length;
  void forEach(void f(int key, E value)) {
 int length = _values.length;
  for (int i = 0; i < length; i++) {
@@ skipping 28 matching lines @@
  abstract class UnmodifiableListError {static UnsupportedError add() => new UnsupportedError("Cannot add to unmodifiable List");
  static UnsupportedError change() => new UnsupportedError("Cannot change the content of an unmodifiable List");
  static UnsupportedError length() => new UnsupportedError("Cannot change length of unmodifiable List");
  static UnsupportedError remove() => new UnsupportedError("Cannot remove from unmodifiable List");
 }
  abstract class NonGrowableListError {static UnsupportedError add() => new UnsupportedError("Cannot add to non-growable List");
  static UnsupportedError length() => new UnsupportedError("Cannot change length of non-growable List");
  static UnsupportedError remove() => new UnsupportedError("Cannot remove from non-growable List");
 }
  external List makeListFixedLength(List growableList) ;