[proxies] Implement Symbol/DONT_ENUM filtering for GetKeys()

src/objects.h

Index: src/objects.h
diff --git a/src/objects.h b/src/objects.h
index 7c1a2f76de89518a11d2f9f083e137c68c30876d..8984edbe50ed57ef666fb842fa4069f4c3a337da 100644
--- a/src/objects.h
+++ b/src/objects.h
@@ -9508,7 +9508,8 @@ class JSProxy: public JSReceiver {
       Handle<JSProxy> proxy, ShouldThrow should_throw);
 
   // ES6 9.5.5
-  static bool GetOwnPropertyDescriptor(LookupIterator* it,
+  static bool GetOwnPropertyDescriptor(Isolate* isolate, Handle<JSProxy> proxy,
+                                       Handle<Name> name,
                                        PropertyDescriptor* desc);
 
   // ES6 9.5.6