Add basic API support for Map & Set

src/api.h

Index: src/api.h
diff --git a/src/api.h b/src/api.h
index 38bb9200364a88061fd77bf22e274b2227cef506..9571cfc40f9b1c09c87bd1772698f9b72eb61e8a 100644
--- a/src/api.h
+++ b/src/api.h
@@ -146,6 +146,8 @@ class RegisteredExtension {
   V(RegExp, JSRegExp)                        \
   V(Object, JSObject)                        \
   V(Array, JSArray)                          \
+  V(Map, JSMap)                              \
+  V(Set, JSSet)                              \
   V(ArrayBuffer, JSArrayBuffer)              \
   V(ArrayBufferView, JSArrayBufferView)      \
   V(TypedArray, JSTypedArray)                \
@@ -202,6 +204,10 @@ class Utils {
       v8::internal::Handle<v8::internal::JSObject> obj);
   static inline Local<Array> ToLocal(
       v8::internal::Handle<v8::internal::JSArray> obj);
+  static inline Local<Map> ToLocal(
+      v8::internal::Handle<v8::internal::JSMap> obj);
+  static inline Local<Set> ToLocal(
+      v8::internal::Handle<v8::internal::JSSet> obj);
   static inline Local<ArrayBuffer> ToLocal(
       v8::internal::Handle<v8::internal::JSArrayBuffer> obj);
   static inline Local<ArrayBufferView> ToLocal(
@@ -356,6 +362,8 @@ MAKE_TO_LOCAL(ToLocal, Symbol, Symbol)
 MAKE_TO_LOCAL(ToLocal, JSRegExp, RegExp)
 MAKE_TO_LOCAL(ToLocal, JSObject, Object)
 MAKE_TO_LOCAL(ToLocal, JSArray, Array)
+MAKE_TO_LOCAL(ToLocal, JSMap, Map)
+MAKE_TO_LOCAL(ToLocal, JSSet, Set)
 MAKE_TO_LOCAL(ToLocal, JSArrayBuffer, ArrayBuffer)
 MAKE_TO_LOCAL(ToLocal, JSArrayBufferView, ArrayBufferView)
 MAKE_TO_LOCAL(ToLocal, JSDataView, DataView)