[runtime] Avoid @@isConcatSpreadable lookup for fast path Array.prototype.concat

src/contexts.h

 // Copyright 2012 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.
 
 #ifndef V8_CONTEXTS_H_
 #define V8_CONTEXTS_H_
 
 #include "src/heap/heap.h"
 #include "src/objects.h"
 
@@ skipping 404 matching lines @@
   void IncrementErrorsThrown();
   int GetErrorsThrown();
 
   // Direct slot access.
   inline JSFunction* closure();
   inline void set_closure(JSFunction* closure);
 
   inline Context* previous();
   inline void set_previous(Context* context);
 
+  inline Object* next_context_link();
+
   inline bool has_extension();
   inline HeapObject* extension();
   inline void set_extension(HeapObject* object);
   JSObject* extension_object();
   JSReceiver* extension_receiver();
   ScopeInfo* scope_info();
   String* catch_name();
 
   inline JSModule* module();
   inline void set_module(JSModule* module);
@@ skipping 136 matching lines @@
 #endif
 
   STATIC_ASSERT(kHeaderSize == Internals::kContextHeaderSize);
   STATIC_ASSERT(EMBEDDER_DATA_INDEX == Internals::kContextEmbedderDataIndex);
 };
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_CONTEXTS_H_