[turbofan] JSCreateClosure doesn't have any JS observable side effects.

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 380 matching lines @@
   node->InsertInput(zone(), 2 + arity, type_info);
   ReplaceWithRuntimeCall(node, Runtime::kNewArray, arity + 3);
 }
 
 
 void JSGenericLowering::LowerJSCreateClosure(Node* node) {
   CreateClosureParameters const& p = CreateClosureParametersOf(node->op());
   CallDescriptor::Flags flags = FrameStateFlagForCall(node);
   Handle<SharedFunctionInfo> const shared_info = p.shared_info();
   node->InsertInput(zone(), 0, jsgraph()->HeapConstant(shared_info));
+  node->RemoveInput(3);  // control
 
-  // Use the FastNewClosurebuiltin only for functions allocated in new
-  // space.
+  // Use the FastNewClosure builtin only for functions allocated in new space.
   if (p.pretenure() == NOT_TENURED) {
     Callable callable = CodeFactory::FastNewClosure(isolate());
     node->InsertInput(zone(), 1,
                       jsgraph()->HeapConstant(p.feedback().vector()));
     node->InsertInput(zone(), 2, jsgraph()->SmiConstant(p.feedback().index()));
     ReplaceWithStubCall(node, callable, flags);
   } else {
     node->InsertInput(zone(), 1,
                       jsgraph()->HeapConstant(p.feedback().vector()));
     node->InsertInput(zone(), 2, jsgraph()->SmiConstant(p.feedback().index()));
@@ skipping 352 matching lines @@
 }
 
 
 MachineOperatorBuilder* JSGenericLowering::machine() const {
   return jsgraph()->machine();
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8