Allow to define accessors on objects.

src/handles.cc

Index: src/handles.cc
diff --git a/src/handles.cc b/src/handles.cc
index 1d4465f3bf296b0ab188729046229a502210c0de..c90365c31acd8795e1ba3d025e299a3f9cc97cd1 100644
--- a/src/handles.cc
+++ b/src/handles.cc
@@ -399,6 +399,11 @@ Handle<JSObject> Copy(Handle<JSObject> obj) {
 }
 
 
+Handle<Object> SetAccessor(Handle<JSObject> obj, Handle<AccessorInfo> info) {
+  CALL_HEAP_FUNCTION(obj->DefineAccessor(*info), Object);
+}
+
+
 // Wrappers for scripts are kept alive and cached in weak global
 // handles referred from proxy objects held by the scripts as long as
 // they are used. When they are not used anymore, the garbage