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

src/heap/heap.cc

Index: src/heap/heap.cc
diff --git a/src/heap/heap.cc b/src/heap/heap.cc
index 8aa6fb85876ef8c7df392e87c0d04fedb5dc28c7..805ce52a4a3521c2d040d8cc894ac11348f5963b 100644
--- a/src/heap/heap.cc
+++ b/src/heap/heap.cc
@@ -2796,8 +2796,13 @@ void Heap::CreateInitialObjects() {
   set_empty_script(*script);
 
   Handle<PropertyCell> cell = factory->NewPropertyCell();
-  cell->set_value(Smi::FromInt(Isolate::kArrayProtectorValid));
-  set_array_protector(*cell);
+  cell->set_value(Smi::FromInt(Isolate::kArrayElementsProtectorValid));
+  set_array_elements_protector(*cell);
+
+  cell = factory->NewPropertyCell();
+  cell->set_value(
+      Smi::FromInt(Isolate::kArrayIsConcatSpreadableProtectorValid));
+  set_array_is_concat_spreadable_protector(*cell);
 
   cell = factory->NewPropertyCell();
   cell->set_value(the_hole_value());