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

src/isolate.h

Index: src/isolate.h
diff --git a/src/isolate.h b/src/isolate.h
index 015f861301b1b05e48b8efbc5955a236147a17fe..12746732eccba8cade01978eb22e6df80ab9bafd 100644
--- a/src/isolate.h
+++ b/src/isolate.h
@@ -969,6 +969,7 @@ class Isolate {
 
   bool IsFastArrayConstructorPrototypeChainIntact();
   bool IsArraySpeciesLookupChainIntact();
+  bool IsArrayIsConcatSpreadableLookupChainIntact();
 
   // On intent to set an element in object, make sure that appropriate
   // notifications occur if the set is on the elements of the array or
@@ -985,6 +986,7 @@ class Isolate {
     UpdateArrayProtectorOnSetElement(object);
   }
   void InvalidateArraySpeciesProtector();
+  void InvalidateArrayIsConcatSpreadableProtector();
 
   // Returns true if array is the initial array prototype in any native context.
   bool IsAnyInitialArrayPrototype(Handle<JSArray> array);
@@ -1116,8 +1118,11 @@ class Isolate {
 
   base::AccountingAllocator* allocator() { return &allocator_; }
 
+  bool IsInContextIndex(Object* object, uint32_t index);
+
  protected:
   explicit Isolate(bool enable_serializer);
+  bool IsArrayOrObjectPrototype(Object* object);
 
  private:
   friend struct GlobalState;