[turbofan] Optimized support for CreateGeneratorObject.

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/compiler/js-generic-lowering.h"
 
 #include "src/ast/ast.h"
 #include "src/builtins/builtins-constructor.h"
 #include "src/code-factory.h"
 #include "src/code-stubs.h"
@@ skipping 405 matching lines @@
     Callable callable =
         CodeFactory::FastNewFunctionContext(isolate(), scope_type);
     node->InsertInput(zone(), 1, jsgraph()->Int32Constant(slot_count));
     ReplaceWithStubCall(node, callable, flags);
   } else {
     node->InsertInput(zone(), 1, jsgraph()->SmiConstant(scope_type));
     ReplaceWithRuntimeCall(node, Runtime::kNewFunctionContext);
   }
 }
 
+void JSGenericLowering::LowerJSCreateGeneratorObject(Node* node) {
+  CallDescriptor::Flags flags = FrameStateFlagForCall(node);
+  Callable callable =
+      Builtins::CallableFor(isolate(), Builtins::kCreateGeneratorObject);
+  ReplaceWithStubCall(node, callable, flags);
+}
 
 void JSGenericLowering::LowerJSCreateIterResultObject(Node* node) {
   ReplaceWithRuntimeCall(node, Runtime::kCreateIterResultObject);
 }
 
 void JSGenericLowering::LowerJSCreateKeyValueArray(Node* node) {
   ReplaceWithRuntimeCall(node, Runtime::kCreateKeyValueArray);
 }
 
 void JSGenericLowering::LowerJSCreateLiteralArray(Node* node) {
@@ skipping 286 matching lines @@
 }
 
 
 MachineOperatorBuilder* JSGenericLowering::machine() const {
   return jsgraph()->machine();
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8