Count closures using the feedback vector cell map, specialize if count==1.

src/compiler/js-create-lowering.cc

Index: src/compiler/js-create-lowering.cc
diff --git a/src/compiler/js-create-lowering.cc b/src/compiler/js-create-lowering.cc
index e1cf237aee1220dad9e19335212d44f8ba8af422..df4c8c13e8065a964ed5ee80d40bdbf2428722aa 100644
--- a/src/compiler/js-create-lowering.cc
+++ b/src/compiler/js-create-lowering.cc
@@ -210,8 +210,6 @@ Reduction JSCreateLowering::Reduce(Node* node) {
       return ReduceJSCreateArguments(node);
     case IrOpcode::kJSCreateArray:
       return ReduceJSCreateArray(node);
-    case IrOpcode::kJSCreateClosure:
-      return ReduceJSCreateClosure(node);
     case IrOpcode::kJSCreateIterResultObject:
       return ReduceJSCreateIterResultObject(node);
     case IrOpcode::kJSCreateKeyValueArray:
@@ -752,48 +750,6 @@ Reduction JSCreateLowering::ReduceJSCreateArray(Node* node) {
   return ReduceNewArrayToStubCall(node, site);
 }
 
-Reduction JSCreateLowering::ReduceJSCreateClosure(Node* node) {
-  if (!FLAG_turbo_lower_create_closure) return NoChange();
-  DCHECK_EQ(IrOpcode::kJSCreateClosure, node->opcode());
-  CreateClosureParameters const& p = CreateClosureParametersOf(node->op());
-  Handle<SharedFunctionInfo> shared = p.shared_info();
-  Node* effect = NodeProperties::GetEffectInput(node);
-  Node* control = NodeProperties::GetControlInput(node);
-  Node* context = NodeProperties::GetContextInput(node);
-
-  int const function_map_index =
-      Context::FunctionMapIndex(shared->language_mode(), shared->kind());
-  Node* function_map = jsgraph()->HeapConstant(
-      handle(Map::cast(native_context()->get(function_map_index)), isolate()));
-
-  FeedbackSlot slot = p.feedback().slot();
-  Node* literals_cell = jsgraph()->HeapConstant(
-      handle(Cell::cast(p.feedback().vector()->Get(slot)), isolate()));
-
-  // Note that it is only safe to embed the raw entry point of the compile
-  // lazy stub into the code, because that stub is immortal and immovable.
-  Node* compile_entry = jsgraph()->PointerConstant(
-      jsgraph()->isolate()->builtins()->CompileLazy()->entry());
-  Node* empty_fixed_array = jsgraph()->EmptyFixedArrayConstant();
-  Node* the_hole = jsgraph()->TheHoleConstant();
-  Node* undefined = jsgraph()->UndefinedConstant();
-  AllocationBuilder a(jsgraph(), effect, control);
-  STATIC_ASSERT(JSFunction::kSize == 9 * kPointerSize);
-  a.Allocate(JSFunction::kSize, p.pretenure());
-  a.Store(AccessBuilder::ForMap(), function_map);
-  a.Store(AccessBuilder::ForJSObjectProperties(), empty_fixed_array);
-  a.Store(AccessBuilder::ForJSObjectElements(), empty_fixed_array);
-  a.Store(AccessBuilder::ForJSFunctionFeedbackVector(), literals_cell);
-  a.Store(AccessBuilder::ForJSFunctionPrototypeOrInitialMap(), the_hole);
-  a.Store(AccessBuilder::ForJSFunctionSharedFunctionInfo(), shared);
-  a.Store(AccessBuilder::ForJSFunctionContext(), context);
-  a.Store(AccessBuilder::ForJSFunctionCodeEntry(), compile_entry);
-  a.Store(AccessBuilder::ForJSFunctionNextFunctionLink(), undefined);
-  RelaxControls(node);
-  a.FinishAndChange(node);
-  return Changed(node);
-}
-
 Reduction JSCreateLowering::ReduceJSCreateIterResultObject(Node* node) {
   DCHECK_EQ(IrOpcode::kJSCreateIterResultObject, node->opcode());
   Node* value = NodeProperties::GetValueInput(node, 0);