[turbofan] Optimized support for CreateGeneratorObject.

src/compiler/js-generic-lowering.cc

Index: src/compiler/js-generic-lowering.cc
diff --git a/src/compiler/js-generic-lowering.cc b/src/compiler/js-generic-lowering.cc
index 9a25b08c63b9d1a5500d342396a327e9b26dbc47..9f240c5a9b66f6d4a79e7c3da80ccf1cd2a36898 100644
--- a/src/compiler/js-generic-lowering.cc
+++ b/src/compiler/js-generic-lowering.cc
@@ -423,6 +423,13 @@ void JSGenericLowering::LowerJSCreateFunctionContext(Node* node) {
   }
 }
 
+void JSGenericLowering::LowerJSCreateGeneratorObject(Node* node) {
+  CallDescriptor::Flags flags = FrameStateFlagForCall(node);
+  Callable callable =
+      Builtins::CallableFor(isolate(), Builtins::kCreateGeneratorObject);
+  node->RemoveInput(4);  // control
+  ReplaceWithStubCall(node, callable, flags);
+}
 
 void JSGenericLowering::LowerJSCreateIterResultObject(Node* node) {
   ReplaceWithRuntimeCall(node, Runtime::kCreateIterResultObject);