[proxies] Make Array.isArray respect proxies.

src/objects.cc

 // Copyright 2013 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/objects.h"
 
 #include <cmath>
 #include <iomanip>
 #include <sstream>
 
@@ skipping 965 matching lines @@
     THROW_NEW_ERROR(isolate,
                     NewTypeError(MessageTemplate::kProxyHandlerTrapMissing,
                                  handler, trap_name),
                     Object);
   }
   // 13. Return handlerProto.
   return handler_proto;
 }
 
 
-bool JSProxy::IsRevoked() {
+bool JSProxy::IsRevoked() const {
   // TODO(neis): Decide on how to represent revocation.  For now, revocation is
   // unsupported.
   DCHECK(target()->IsJSReceiver());
   DCHECK(handler()->IsJSReceiver());
   return false;
 }
 
 
 MaybeHandle<Object> Object::GetPropertyWithAccessor(
     LookupIterator* it, LanguageMode language_mode) {
@@ skipping 18058 matching lines @@
   if (cell->value() != *new_value) {
     cell->set_value(*new_value);
     Isolate* isolate = cell->GetIsolate();
     cell->dependent_code()->DeoptimizeDependentCodeGroup(
         isolate, DependentCode::kPropertyCellChangedGroup);
   }
 }
 
 }  // namespace internal
 }  // namespace v8