Expose Value::IsArgumentsObject in V8 API.

test/cctest/test-api.cc

Index: test/cctest/test-api.cc
diff --git a/test/cctest/test-api.cc b/test/cctest/test-api.cc
index 45c5d467d3143420408f858c91e6baa7e0d304ea..5dd03aa2a4c5fd2359e8575e493558b76cd5c74a 100644
--- a/test/cctest/test-api.cc
+++ b/test/cctest/test-api.cc
@@ -1539,6 +1539,19 @@ THREADED_TEST(IsNativeError) {
 }
 
 
+THREADED_TEST(ArgumentsObject) {
+  LocalContext env;
+  v8::HandleScope scope(env->GetIsolate());
+  v8::Handle<Value> arguments_object =
+      CompileRun("var out = 0; (function(){ out = arguments; })(1,2,3); out;");
+  CHECK(arguments_object->IsArgumentsObject());
+  v8::Handle<Value> array = CompileRun("[1,2,3]");
+  CHECK(!array->IsArgumentsObject());
+  v8::Handle<Value> object = CompileRun("{a:42}");
+  CHECK(!object->IsArgumentsObject());
+}
+
+
 THREADED_TEST(StringObject) {
   LocalContext env;
   v8::HandleScope scope(env->GetIsolate());