[proxies] Implement [[Enumerate]] and [[OwnPropertyKeys]]

src/objects.h

Index: src/objects.h
diff --git a/src/objects.h b/src/objects.h
index 410e2f12aba6a7fcbf4d2919a69d824002e0305d..c198a8b52cf4434835628e137361edd3a85bcc80 100644
--- a/src/objects.h
+++ b/src/objects.h
@@ -9524,6 +9524,16 @@ class JSProxy: public JSReceiver {
   MUST_USE_RESULT static Maybe<bool> DeletePropertyOrElement(
       Handle<JSProxy> proxy, Handle<Name> name, LanguageMode language_mode);
 
+  // ES6 9.5.11
+  static bool Enumerate(Isolate* isolate, Handle<JSReceiver> receiver,
+                        Handle<JSProxy> proxy, KeyAccumulator* accumulator);
+
+  // ES6 9.5.12
+  static bool OwnPropertyKeys(Isolate* isolate, Handle<JSReceiver> receiver,
+                              Handle<JSProxy> proxy, KeyFilter filter,
+                              Enumerability enum_policy,
+                              KeyAccumulator* accumulator);
+
   MUST_USE_RESULT static MaybeHandle<Object> GetPropertyWithHandler(
       Handle<JSProxy> proxy,
       Handle<Object> receiver,