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

src/heap/heap.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_HEAP_HEAP_H_
 #define V8_HEAP_HEAP_H_
 
 #include <cmath>
 #include <map>
 
@@ skipping 171 matching lines @@
   V(SeededNumberDictionary, empty_slow_element_dictionary,                     \
     EmptySlowElementDictionary)                                                \
   V(FixedArray, materialized_objects, MaterializedObjects)                     \
   V(FixedArray, microtask_queue, MicrotaskQueue)                               \
   V(TypeFeedbackVector, dummy_vector, DummyVector)                             \
   V(FixedArray, cleared_optimized_code_map, ClearedOptimizedCodeMap)           \
   V(FixedArray, detached_contexts, DetachedContexts)                           \
   V(ArrayList, retained_maps, RetainedMaps)                                    \
   V(WeakHashTable, weak_object_to_code_table, WeakObjectToCodeTable)           \
   V(PropertyCell, array_protector, ArrayProtector)                             \
+  V(PropertyCell, array_is_concat_spreadable_protector,                        \
+    ArrayIsConcatSpreadableProtector)                                          \
   V(PropertyCell, empty_property_cell, EmptyPropertyCell)                      \
   V(Object, weak_stack_trace_list, WeakStackTraceList)                         \
   V(Object, noscript_shared_function_infos, NoScriptSharedFunctionInfos)       \
   V(Map, bytecode_array_map, BytecodeArrayMap)                                 \
   V(WeakCell, empty_weak_cell, EmptyWeakCell)                                  \
   V(PropertyCell, species_protector, SpeciesProtector)
 
 // Entries in this list are limited to Smis and are not visited during GC.
 #define SMI_ROOT_LIST(V)                                                   \
   V(Smi, stack_limit, StackLimit)                                          \
@@ skipping 2452 matching lines @@
   friend class LargeObjectSpace;
   friend class NewSpace;
   friend class PagedSpace;
   DISALLOW_COPY_AND_ASSIGN(AllocationObserver);
 };
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_HEAP_HEAP_H_