Move Arrays class to private library.

sdk/lib/collection/collections.dart

Index: sdk/lib/collection/collections.dart
diff --git a/sdk/lib/collection/collections.dart b/sdk/lib/collection/collections.dart
index 949b69dfa0128442d93ee878aba2df1158da614b..6300b11dab077b2cdcdd73bf82f648b4b9854be7 100644
--- a/sdk/lib/collection/collections.dart
+++ b/sdk/lib/collection/collections.dart
@@ -347,13 +347,35 @@ class IterableMixinWorkaround {
     return new SkipWhileIterable(iterable, test);
   }
 
-  static Iterable reversedList(List l) {
-    return new ReversedListIterable(l);
+  static Iterable reversedList(List list) {
+    return new ReversedListIterable(list);
   }
 
-  static void sortList(List l, int compare(a, b)) {
+  static void sortList(List list, int compare(a, b)) {
     if (compare == null) compare = Comparable.compare;
-    Sort.sort(l, compare);
+    Sort.sort(list, compare);
+  }
+
+  static int indexOfList(List list, var element, int start) {
+    return Arrays.indexOf(list, element, start, list.length);
+  }
+
+  static int lastIndexOfList(List list, var element, int start) {
+    if (start == null) start = list.length - 1;
+    return Arrays.lastIndexOf(list, element, start);
+  }
+
+  static void setRangeList(List list, int start, int length,
+                           List from, int startFrom) {
+    if (length == 0) return;
+
+    if (length < 0) throw new ArgumentError(length);
+    if (start < 0) throw new RangeError.value(start);
+    if (start + length > list.length) {
+      throw new RangeError.value(start + length);
+    }
+
+    Arrays.copy(from, startFrom, list, start, length);
   }
 
   static Map<int, dynamic> asMapList(List l) {