Fix sublist check, add missing methods and add tests.

runtime/lib/typed_data.dart

Index: runtime/lib/typed_data.dart
diff --git a/runtime/lib/typed_data.dart b/runtime/lib/typed_data.dart
index 15a8debb21b315087e2fbac1073d58a5826c3871..fef87bc2e57abe6296ddc295e20174cafb0f5053 100644
--- a/runtime/lib/typed_data.dart
+++ b/runtime/lib/typed_data.dart
@@ -351,6 +351,10 @@ abstract class _TypedListBase {
     return IterableMixinWorkaround.singleWhere(this, test);
   }
 
+  Iterable<num> get reversed {
+    return IterableMixinWorkaround.reversedList(this);
+  }
+
   num elementAt(int index) {
     return this[index];
   }
@@ -474,6 +478,10 @@ abstract class _TypedListBase {
     return new Set.from(this);
   }
 
+  Map<int, num> asMap() {
+    return IterableMixinWorkaround.asMapList(this);
+  }
+
   List sublist(int start, [int end]) {
     if (end == null) end = length;
     int length = end - start;