[turbofan] Optimized support for CreateGeneratorObject.

test/unittests/compiler/js-intrinsic-lowering-unittest.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/access-builder.h"
 #include "src/compiler/diamond.h"
 #include "src/compiler/js-graph.h"
 #include "src/compiler/js-intrinsic-lowering.h"
 #include "src/compiler/js-operator.h"
 #include "test/unittests/compiler/graph-unittest.h"
@@ skipping 126 matching lines @@
   Node* const context = Parameter(1);
   Node* const effect = graph()->start();
   Node* const control = graph()->start();
   Reduction const r = Reduce(graph()->NewNode(
       javascript()->CallRuntime(Runtime::kInlineIsJSReceiver, 1), input,
       context, effect, control));
   ASSERT_TRUE(r.Changed());
   EXPECT_THAT(r.replacement(), IsObjectIsReceiver(input));
 }
 
+// -----------------------------------------------------------------------------
+// %_CreateJSGeneratorObject
+
+TEST_F(JSIntrinsicLoweringTest, InlineCreateJSGeneratorObject) {
+  Node* const function = Parameter(0);
+  Node* const receiver = Parameter(1);
+  Node* const context = Parameter(2);
+  Node* const effect = graph()->start();
+  Node* const control = graph()->start();
+  Reduction const r = Reduce(graph()->NewNode(
+      javascript()->CallRuntime(Runtime::kInlineCreateJSGeneratorObject, 2),
+      function, receiver, context, effect, control));
+  ASSERT_TRUE(r.Changed());
+  EXPECT_EQ(IrOpcode::kJSCreateGeneratorObject,
+            r.replacement()->op()->opcode());
+}
+
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8