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

src/bootstrapper.cc

 // Copyright 2014 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/bootstrapper.h"
 
 #include "src/accessors.h"
 #include "src/api-natives.h"
 #include "src/code-stubs.h"
 #include "src/extensions/externalize-string-extension.h"
@@ skipping 789 matching lines @@
   ReplaceAccessors(map, factory()->arguments_string(), rw_attribs, accessors);
   ReplaceAccessors(map, factory()->caller_string(), rw_attribs, accessors);
 }
 
 
 static void AddToWeakNativeContextList(Context* context) {
   DCHECK(context->IsNativeContext());
   Heap* heap = context->GetIsolate()->heap();
 #ifdef DEBUG
   { // NOLINT
-    DCHECK(context->get(Context::NEXT_CONTEXT_LINK)->IsUndefined());
+    DCHECK(context->next_context_link()->IsUndefined());
     // Check that context is not in the list yet.
     for (Object* current = heap->native_contexts_list();
          !current->IsUndefined();
-         current = Context::cast(current)->get(Context::NEXT_CONTEXT_LINK)) {
+         current = Context::cast(current)->next_context_link()) {
       DCHECK(current != context);
     }
   }
 #endif
   context->set(Context::NEXT_CONTEXT_LINK, heap->native_contexts_list(),
                UPDATE_WEAK_WRITE_BARRIER);
   heap->set_native_contexts_list(context);
 }
 
 
@@ skipping 2805 matching lines @@
 }
 
 
 // Called when the top-level V8 mutex is destroyed.
 void Bootstrapper::FreeThreadResources() {
   DCHECK(!IsActive());
 }
 
 }  // namespace internal
 }  // namespace v8