Expose Value::IsArgumentsObject in V8 API.

src/api.cc

Index: src/api.cc
diff --git a/src/api.cc b/src/api.cc
index 538071af1924a2dd24b627a6bcfb813a9bcfc2fc..00db4e316e00e2bc965f70d3e825ab2da9b65242 100644
--- a/src/api.cc
+++ b/src/api.cc
@@ -2383,6 +2383,14 @@ bool Value::IsNumber() const {
 }
 
 
+bool Value::IsArgumentsObject() const {
+  i::Handle<i::Object> obj = Utils::OpenHandle(this);
+  if (!obj->IsHeapObject()) return false;
+  i::Isolate* isolate = i::HeapObject::cast(*obj)->GetIsolate();
+  return obj->HasSpecificClassOf(isolate->heap()->Arguments_string());

[Yang, 2014/08/12 10:53:46]

I don't think this is fool-proof. You could always just create a constructor
named "Arguments".

How about checking against the sloppy_arguments_map or the strict_arguments_map?

And I noticed how Heap::Arguments_string is not even used. We could remove that
root entry.

+}
+
+
 bool Value::IsBoolean() const {
   return Utils::OpenHandle(this)->IsBoolean();
 }