Fix a bug in typecasts in the VM.

tests/language/cast2_test.dart

Index: tests/language/cast2_test.dart
diff --git a/tests/language/cast2_test.dart b/tests/language/cast2_test.dart
index 397ac4543ff4c3490b61688db66ebe655ef4aa8f..b2aa11f6d8cff760b62c8b611965751d022feba8 100644
--- a/tests/language/cast2_test.dart
+++ b/tests/language/cast2_test.dart
@@ -3,10 +3,15 @@
 // BSD-style license that can be found in the LICENSE file.
 // Dart test program for constructors and initializers.
 
+import "package:expect/expect.dart";
+
 // Test 'expression as Type' casts.
 
 class C {
   final int foo = 42;
+
+  int val = 0;
+  void inc() { ++val; }
 }
 
 class D extends C {
@@ -18,6 +23,10 @@ main() {
   Object od = new D();
 
   (oc as dynamic).bar;  /// 01: runtime error
-}
-
 
+  // Casts should always evaluate the left-hand side, if only for its effects.
+  oc.inc() as dynamic;
+  Expect.equals(1, oc.val);
+  oc.inc() as Object;
+  Expect.equals(2, oc.val);
+}