Move ArrayBuffer.prototype.slice implementation to C++

src/objects.cc

Index: src/objects.cc
diff --git a/src/objects.cc b/src/objects.cc
index 6e9a12001de5ba66e2b4907e72d09637a8906822..137ea98b0b826e256cdd00e9b96cbd7a45821ac0 100644
--- a/src/objects.cc
+++ b/src/objects.cc
@@ -2331,6 +2331,42 @@ MaybeHandle<Object> Object::ArraySpeciesConstructor(
   }
 }
 
+// ES6 section 7.3.20 SpeciesConstructor ( O, defaultConstructor )
+MUST_USE_RESULT MaybeHandle<Object> Object::SpeciesConstructor(
+    Isolate* isolate, Handle<JSReceiver> recv,
+    Handle<JSFunction> default_ctor) {
+  Handle<Object> ctor_obj;
+  ASSIGN_RETURN_ON_EXCEPTION(
+      isolate, ctor_obj,
+      JSObject::GetProperty(recv, isolate->factory()->constructor_string()),
+      Object);
+
+  if (ctor_obj->IsUndefined(isolate)) return default_ctor;
+
+  if (!ctor_obj->IsJSReceiver()) {
+    THROW_NEW_ERROR(isolate,
+                    NewTypeError(MessageTemplate::kConstructorNotReceiver),
+                    Object);
+  }
+
+  Handle<JSReceiver> ctor = Handle<JSReceiver>::cast(ctor_obj);
+
+  Handle<Object> species;
+  ASSIGN_RETURN_ON_EXCEPTION(
+      isolate, species,
+      JSObject::GetProperty(ctor, isolate->factory()->species_symbol()),
+      Object);
+
+  if (species->IsNullOrUndefined(isolate)) {
+    return default_ctor;
+  }
+
+  if (species->IsConstructor()) return species;
+
+  THROW_NEW_ERROR(
+      isolate, NewTypeError(MessageTemplate::kSpeciesNotConstructor), Object);
+}
+
 bool Object::IterationHasObservableEffects() {
   // Check that this object is an array.
   if (!IsJSArray()) return true;