Treat Object and dynamic similarly

test/dart_codegen/expect/collection/set.dart

 part of dart.collection;
  abstract class SetMixin<E> implements Set<E> {bool add(E element);
  bool contains(Object element);
  E lookup(E element);
  bool remove(Object element);
  Iterator<E> get iterator;
  Set<E> toSet();
  int get length;
  bool get isEmpty => length == 0;
  bool get isNotEmpty => length != 0;
@@ skipping 11 matching lines @@
    for (Object o in elements) {
     toRemove.remove(o);
     }
    removeAll(toRemove);
   }
  void removeWhere(bool test(E element)) {
   List toRemove = [];
    for (E element in this) {
     if (test(element)) toRemove.add(element);
     }
-   removeAll(DEVC$RT.cast(toRemove, DEVC$RT.type((List<dynamic> _) {
-    }
-  ), DEVC$RT.type((Iterable<Object> _) {
-    }
-  ), "CastDynamic", """line 77, column 15 of dart:collection/set.dart: """, toRemove is Iterable<Object>, true));
+   removeAll(toRemove);
   }
  void retainWhere(bool test(E element)) {
   List toRemove = [];
    for (E element in this) {
     if (!test(element)) toRemove.add(element);
     }
-   removeAll(DEVC$RT.cast(toRemove, DEVC$RT.type((List<dynamic> _) {
-    }
-  ), DEVC$RT.type((Iterable<Object> _) {
-    }
-  ), "CastDynamic", """line 85, column 15 of dart:collection/set.dart: """, toRemove is Iterable<Object>, true));
+   removeAll(toRemove);
   }
  bool containsAll(Iterable<Object> other) {
   for (Object o in other) {
     if (!contains(o)) return false;
     }
    return true;
   }
  Set<E> union(Set<E> other) {
   return toSet()..addAll(other);
   }
@@ skipping 154 matching lines @@
    int elementIndex = 0;
    for (E element in this) {
     if (index == elementIndex) return element;
      elementIndex++;
     }
    throw new RangeError.index(index, this, "index", null, elementIndex);
   }
 }
  abstract class SetBase<E> extends SetMixin<E> {static String setToString(Set set) => IterableBase.iterableToFullString(set, '{', '}');
 }