[stubs] Introduce a dedicated FastNewObjectStub.

src/compiler/js-generic-lowering.cc

 // Copyright 2014 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/code-factory.h"
 #include "src/code-stubs.h"
 #include "src/compiler/common-operator.h"
 #include "src/compiler/js-generic-lowering.h"
 #include "src/compiler/js-graph.h"
 #include "src/compiler/machine-operator.h"
@@ skipping 490 matching lines @@
   node->ReplaceInput(2, NodeProperties::GetValueInput(node, 1));
   node->ReplaceInput(1, jsgraph()->Int32Constant(Context::SlotOffset(
                             static_cast<int>(access.index()))));
   NodeProperties::ChangeOp(
       node, machine()->Store(StoreRepresentation(MachineRepresentation::kTagged,
                                                  kFullWriteBarrier)));
 }
 
 
 void JSGenericLowering::LowerJSCreate(Node* node) {
-  ReplaceWithRuntimeCall(node, Runtime::kNewObject);
+  CallDescriptor::Flags flags = AdjustFrameStatesForCall(node);
+  Callable callable = CodeFactory::FastNewObject(isolate());
+  ReplaceWithStubCall(node, callable, flags);
 }
 
 
 void JSGenericLowering::LowerJSCreateArguments(Node* node) {
   CreateArgumentsType const type = CreateArgumentsTypeOf(node->op());
   switch (type) {
     case CreateArgumentsType::kMappedArguments:
       ReplaceWithRuntimeCall(node, Runtime::kNewSloppyArguments_Generic);
       break;
     case CreateArgumentsType::kUnmappedArguments:
@@ skipping 337 matching lines @@
 }
 
 
 MachineOperatorBuilder* JSGenericLowering::machine() const {
   return jsgraph()->machine();
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8