[es6] Tail calls support.

src/compiler/bytecode-graph-builder.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/bytecode-graph-builder.h"
 
 #include "src/compiler/bytecode-branch-analysis.h"
 #include "src/compiler/linkage.h"
 #include "src/compiler/operator-properties.h"
 #include "src/interpreter/bytecodes.h"
@@ skipping 1179 matching lines @@
   FrameStateBeforeAndAfter states(this, iterator);
   // TODO(rmcilroy): Set receiver_hint correctly based on whether the receiver
   // register has been loaded with null / undefined explicitly or we are sure it
   // is not null / undefined.
   ConvertReceiverMode receiver_hint = ConvertReceiverMode::kAny;
   Node* callee = environment()->LookupRegister(iterator.GetRegisterOperand(0));
   interpreter::Register receiver = iterator.GetRegisterOperand(1);
   size_t arg_count = iterator.GetCountOperand(2);
   VectorSlotPair feedback = CreateVectorSlotPair(iterator.GetIndexOperand(3));
 
+  // TODO(ishell): provide correct tail_call_mode value to CallFunction.
   const Operator* call = javascript()->CallFunction(
       arg_count + 2, language_mode(), feedback, receiver_hint);
   Node* value = ProcessCallArguments(call, callee, receiver, arg_count + 2);
   environment()->BindAccumulator(value, &states);
 }
 
 
 void BytecodeGraphBuilder::VisitCall(
     const interpreter::BytecodeArrayIterator& iterator) {
   BuildCall(iterator);
@@ skipping 891 matching lines @@
 
 void BytecodeGraphBuilder::UpdateControlDependencyToLeaveFunction(Node* exit) {
   if (environment()->IsMarkedAsUnreachable()) return;
   environment()->MarkAsUnreachable();
   exit_controls_.push_back(exit);
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8