Report errors and warnings for hiding elements, issue 572.

compiler/javatests/com/google/dart/compiler/backend/js/testListSubTypeExprOpt.dart

Index: compiler/javatests/com/google/dart/compiler/backend/js/testListSubTypeExprOpt.dart
diff --git a/compiler/javatests/com/google/dart/compiler/backend/js/testListSubTypeExprOpt.dart b/compiler/javatests/com/google/dart/compiler/backend/js/testListSubTypeExprOpt.dart
index 2cb6e9676fc9aab9253dcec327c0392f68222242..e64575821b69b89c42266f75c23676bb73805f73 100644
--- a/compiler/javatests/com/google/dart/compiler/backend/js/testListSubTypeExprOpt.dart
+++ b/compiler/javatests/com/google/dart/compiler/backend/js/testListSubTypeExprOpt.dart
@@ -14,16 +14,16 @@ class MyList<T> implements List<T> {
   void copyFrom(List<Object> src, int srcStart, int dstStart, int count) {}
   int indexOf(T element, [int start = 0]) { return null; }
   int lastIndexOf(T element, [int start = null]) { return null; }
-  void setRange(int start, int length, List from, [int startFrom = 0]) {}
-  void removeRange(int start, int length) {}
-  void insertRange(int start, int length, [initialValue = null]) {}
-  List getRange(int start, int length) { return null; }
+  void setRange(int start, int length_, List from, [int startFrom = 0]) {}
+  void removeRange(int start, int length_) {}
+  void insertRange(int start, int length_, [initialValue = null]) {}
+  List getRange(int start, int length_) { return null; }
   void clear() {}
   T removeLast() { return null; }
   T last() { return null; }
   void forEach(void f(T)) {}
   Collection<T> filter(bool f(T)) { return null; }
-  bool every(bool (T)) { return null; }
+  bool every(bool f(T)) { return null; }
   bool some(bool f(T)) { return null; }
   bool isEmpty() { return null; }
   Iterator<T> iterator() { return null; }