[proxies] allow duplicate keys for [[OwnPropertyKeys]] trap.

src/runtime/runtime-forin.cc

 // Copyright 2015 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/runtime/runtime-utils.h"
 
 #include "src/arguments.h"
 #include "src/factory.h"
 #include "src/isolate-inl.h"
 #include "src/objects-inl.h"
 
 namespace v8 {
 namespace internal {
 
 namespace {
 
 // Returns either a FixedArray or, if the given {receiver} has an enum cache
 // that contains all enumerable properties of the {receiver} and its prototypes
 // have none, the map of the {receiver}. This is used to speed up the check for
 // deletions during a for-in.
 MaybeHandle<HeapObject> Enumerate(Handle<JSReceiver> receiver) {
   Isolate* const isolate = receiver->GetIsolate();
   // Test if we have an enum cache for {receiver}.
   if (!receiver->IsSimpleEnum()) {
     Handle<FixedArray> keys;
     ASSIGN_RETURN_ON_EXCEPTION(
-        isolate, keys, JSReceiver::GetKeys(receiver, JSReceiver::INCLUDE_PROTOS,
-                                           ENUMERABLE_STRINGS),
+        isolate, keys,
+        JSReceiver::GetKeys(receiver, INCLUDE_PROTOS, ENUMERABLE_STRINGS),
         HeapObject);
     // Test again, since cache may have been built by GetKeys() calls above.
     if (!receiver->IsSimpleEnum()) return keys;
   }
   return handle(receiver->map(), isolate);
 }
 
 
 MaybeHandle<Object> Filter(Handle<JSReceiver> receiver, Handle<Object> key) {
   Isolate* const isolate = receiver->GetIsolate();
@@ skipping 94 matching lines @@
   SealHandleScope scope(isolate);
   DCHECK_EQ(1, args.length());
   CONVERT_SMI_ARG_CHECKED(index, 0);
   DCHECK_LE(0, index);
   DCHECK_LT(index, Smi::kMaxValue);
   return Smi::FromInt(index + 1);
 }
 
 }  // namespace internal
 }  // namespace v8