Add debug mirror support for ES6 Map/Set iterators.

src/api.cc

Index: src/api.cc
diff --git a/src/api.cc b/src/api.cc
index c9231a31e75d2f637c8afd36904441d1cddd3548..2c8009e1d3cd80ccadb86940476edb47a4e148be 100644
--- a/src/api.cc
+++ b/src/api.cc
@@ -2571,6 +2571,16 @@ bool Value::IsGeneratorObject() const {
 }
 
 
+bool Value::IsMapIterator() const {
+  return Utils::OpenHandle(this)->IsJSMapIterator();
+}
+
+
+bool Value::IsSetIterator() const {
+  return Utils::OpenHandle(this)->IsJSSetIterator();
+}
+
+
 Local<String> Value::ToString(Isolate* v8_isolate) const {
   i::Handle<i::Object> obj = Utils::OpenHandle(this);
   i::Handle<i::Object> str;