Fix "is Object" to always be true in Dart.

frog/value.dart

Index: frog/value.dart
diff --git a/frog/value.dart b/frog/value.dart
index 684fecbcde3c10617ac0577a3a171089fcb6e765..4466f3f3fb9d916b9e998cb46e3b054e9703ad8a 100644
--- a/frog/value.dart
+++ b/frog/value.dart
@@ -391,16 +391,21 @@ function \$assert_${toType.name}(x) {
       [bool isTrue=true, bool forceCheck=false]) {
     // TODO(jimhug): Optimize away tests that will always pass unless
     //    forceCheck is true.
+
     if (toType.isVar) {
       world.error('can not resolve type', span);
-      return new EvaluatedValue(world.nonNullBool, true, 'true', null);
     }
 
-    if (toType is ParameterType) {
-      return new EvaluatedValue(world.nonNullBool, true, 'true', null);
+    String testCode = null;
+    if (toType.isVar || toType.isObject || toType is ParameterType) {
+      // Note: everything is an Object, including null.
+      if (needsTemp) {
+        return new Value(world.nonNullBool, '($code, true)', span);

[Siggi Cherem (dart-lang), 2011/11/17 16:55:57]

can you explain to me a bit more ($code, true)? is this so that we get the side
effects, then return true?

[Jennifer Messerly, 2011/11/17 18:18:51]

Yes, exactly.

+      } else {
+        return new EvaluatedValue(world.nonNullBool, true, 'true', null);
+      }
     }
 
-    String testCode = null;
     if (toType.library.isCore) {
       var typeofName = toType.typeofName;
       if (typeofName != null) {