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

src/elements.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_ELEMENTS_H_
 #define V8_ELEMENTS_H_
 
 #include "src/elements-kind.h"
 #include "src/heap/heap.h"
 #include "src/isolate.h"
@@ skipping 110 matching lines @@
   virtual void Reconfigure(Handle<JSObject> object,
                            Handle<FixedArrayBase> backing_store, uint32_t entry,
                            Handle<Object> value,
                            PropertyAttributes attributes) = 0;
 
   virtual void Add(Handle<JSObject> object, uint32_t index,
                    Handle<Object> value, PropertyAttributes attributes,
                    uint32_t new_capacity) = 0;
 
   static Handle<JSArray> Concat(Isolate* isolate, Arguments* args,
-                                uint32_t concat_size);
+                                uint32_t concat_size, uint32_t result_length);
 
   virtual uint32_t Push(Handle<JSArray> receiver, Arguments* args,
                         uint32_t push_size) = 0;
 
   virtual uint32_t Unshift(Handle<JSArray> receiver,
                            Arguments* args, uint32_t unshift_size) = 0;
 
   virtual Handle<JSArray> Slice(Handle<JSObject> receiver,
                                 uint32_t start, uint32_t end) = 0;
 
@@ skipping 45 matching lines @@
                      bool allow_appending = false);
 
 MUST_USE_RESULT MaybeHandle<Object> ArrayConstructInitializeElements(
     Handle<JSArray> array,
     Arguments* args);
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_ELEMENTS_H_