[turbofan] Introduce JSCallForwardVarargs operator.

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 512 matching lines @@
   Node* new_target = node->InputAt(arg_count + 1);
   Node* receiver = jsgraph()->UndefinedConstant();
   node->RemoveInput(arg_count + 1);  // Drop new target.
   node->InsertInput(zone(), 0, stub_code);
   node->InsertInput(zone(), 2, new_target);
   node->InsertInput(zone(), 3, stub_arity);
   node->InsertInput(zone(), 4, receiver);
   NodeProperties::ChangeOp(node, common()->Call(desc));
 }
 
+void JSGenericLowering::LowerJSCallForwardVarargs(Node* node) {
+  CallForwardVarargsParameters p = CallForwardVarargsParametersOf(node->op());
+  Callable callable = CodeFactory::CallForwardVarargs(isolate());
+  CallDescriptor::Flags flags = FrameStateFlagForCall(node);
+  if (p.tail_call_mode() == TailCallMode::kAllow) {
+    flags |= CallDescriptor::kSupportsTailCalls;
+  }
+  CallDescriptor* desc = Linkage::GetStubCallDescriptor(
+      isolate(), zone(), callable.descriptor(), 1, flags);
+  Node* stub_code = jsgraph()->HeapConstant(callable.code());
+  Node* start_index = jsgraph()->Uint32Constant(p.start_index());
+  node->InsertInput(zone(), 0, stub_code);
+  node->InsertInput(zone(), 2, start_index);
+  NodeProperties::ChangeOp(node, common()->Call(desc));
+}
+
 void JSGenericLowering::LowerJSCallFunction(Node* node) {
   CallFunctionParameters const& p = CallFunctionParametersOf(node->op());
   int const arg_count = static_cast<int>(p.arity() - 2);
   ConvertReceiverMode const mode = p.convert_mode();
   Callable callable = CodeFactory::Call(isolate(), mode);
   CallDescriptor::Flags flags = FrameStateFlagForCall(node);
   if (p.tail_call_mode() == TailCallMode::kAllow) {
     flags |= CallDescriptor::kSupportsTailCalls;
   }
   CallDescriptor* desc = Linkage::GetStubCallDescriptor(
@@ skipping 124 matching lines @@
 }
 
 
 MachineOperatorBuilder* JSGenericLowering::machine() const {
   return jsgraph()->machine();
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8