[turbofan] Use CheckMaps for the COW check on elements.

src/compiler/js-native-context-specialization.cc

 // Copyright 2015 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.
 
 #include "src/compiler/js-native-context-specialization.h"
 
 #include "src/accessors.h"
 #include "src/code-factory.h"
 #include "src/compilation-dependencies.h"
 #include "src/compiler/access-builder.h"
@@ skipping 954 matching lines @@
   MapList const& receiver_maps = access_info.receiver_maps();
 
   // Load the elements for the {receiver}.
   Node* elements = effect = graph()->NewNode(
       simplified()->LoadField(AccessBuilder::ForJSObjectElements()), receiver,
       effect, control);
 
   // Don't try to store to a copy-on-write backing store.
   if (access_mode == AccessMode::kStore &&
       IsFastSmiOrObjectElementsKind(elements_kind)) {
-    Node* elements_map = effect =
-        graph()->NewNode(simplified()->LoadField(AccessBuilder::ForMap()),
-                         elements, effect, control);
-    Node* check = graph()->NewNode(
-        simplified()->ReferenceEqual(Type::Any()), elements_map,
-        jsgraph()->HeapConstant(factory()->fixed_array_map()));
-    effect = graph()->NewNode(simplified()->CheckIf(), check, effect, control);
+    effect = graph()->NewNode(
+        simplified()->CheckMaps(1), elements,
+        jsgraph()->HeapConstant(factory()->fixed_array_map()), effect, control);
   }
 
   if (IsFixedTypedArrayElementsKind(elements_kind)) {
     // Load the {receiver}s length.
     Node* length = effect = graph()->NewNode(
         simplified()->LoadField(AccessBuilder::ForJSTypedArrayLength()),
         receiver, effect, control);
 
     // Check if the {receiver}s buffer was neutered.
     Node* buffer = effect = graph()->NewNode(
@@ skipping 347 matching lines @@
 }
 
 
 SimplifiedOperatorBuilder* JSNativeContextSpecialization::simplified() const {
   return jsgraph()->simplified();
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8