[turbofan] Introduce CheckUnless.

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 555 matching lines @@
         Node* check =
             graph()->NewNode(simplified()->ReferenceEqual(Type::Any()),
                              receiver_map, jsgraph()->Constant(map));
         if (--num_classes == 0 && num_transitions == 0 &&
             j == access_infos.size() - 1) {
           // Last map check on the fallthrough control path, do a conditional
           // eager deoptimization exit here.
           // TODO(turbofan): This is ugly as hell! We should probably introduce
           // macro-ish operators for property access that encapsulate this whole
           // mess.
-          Node* deoptimize =
-              graph()->NewNode(common()->DeoptimizeUnless(), check, frame_state,
-                               effect, fallthrough_control);
-          this_controls.push_back(deoptimize);
+          Node* deoptimize = graph()->NewNode(
+              simplified()->CheckUnless(), check, effect, fallthrough_control);
+          this_controls.push_back(fallthrough_control);
           this_effects.push_back(deoptimize);
           fallthrough_control = nullptr;
         } else {
           Node* branch =
               graph()->NewNode(common()->Branch(), check, fallthrough_control);
           this_controls.push_back(graph()->NewNode(common()->IfTrue(), branch));
           this_effects.push_back(effect);
           fallthrough_control = graph()->NewNode(common()->IfFalse(), branch);
         }
         if (!map->IsJSArrayMap()) receiver_is_jsarray = false;
@@ skipping 501 matching lines @@
 }
 
 
 SimplifiedOperatorBuilder* JSNativeContextSpecialization::simplified() const {
   return jsgraph()->simplified();
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8