Implement async file API on top of isolates.

tests/corelib/src/ListSetRangeTest.dart

Index: tests/corelib/src/ListSetRangeTest.dart
diff --git a/tests/corelib/src/ListSetRangeTest.dart b/tests/corelib/src/ListSetRangeTest.dart
index d728f2c3a9f6eb7cc9840adc65a3ed508b5ba1c8..ad004a380564be7567a2a5b998eb00c0eceb4c91 100644
--- a/tests/corelib/src/ListSetRangeTest.dart
+++ b/tests/corelib/src/ListSetRangeTest.dart
@@ -52,6 +52,8 @@ main() {
   Expect.listEquals([1, 9, 10, 6], list);
 
   testNegativeIndices();
+
+  testNonExtendableList();
 }
 
 void expectIOORE(Function f) {
@@ -78,3 +80,11 @@ void testNegativeIndices() {
   list.setRange(0, 0, [1], -1);
   Expect.listEquals([1, 2], list);
 }
+
+void testNonExtendableList() {
+  var list = new List<int>(6);
+  Expect.listEquals([null, null, null, null, null, null], list);
+  list.setRange(0, 3, [1, 2, 3, 4]);
+  list.setRange(3, 3, [1, 2, 3, 4]);
+  Expect.listEquals([1, 2, 3, 1, 2, 3], list);
+}