[es6] Tail calls support.

src/ic/ic-state.h

 // Copyright 2012 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.
 
 #ifndef V8_IC_STATE_H_
 #define V8_IC_STATE_H_
 
 #include "src/macro-assembler.h"
 
 namespace v8 {
 namespace internal {
 
 
 const int kMaxKeyedPolymorphism = 4;
 
 
 class ICUtility : public AllStatic {
  public:
   // Clear the inline cache to initial state.
   static void Clear(Isolate* isolate, Address address, Address constant_pool);
 };
 
 
 class CallICState final BASE_EMBEDDED {
  public:
   explicit CallICState(ExtraICState extra_ic_state)
       : bit_field_(extra_ic_state) {}
-  CallICState(int argc, ConvertReceiverMode convert_mode)
+  CallICState(int argc, ConvertReceiverMode convert_mode,
+              TailCallMode tail_call_mode)
       : bit_field_(ArgcBits::encode(argc) |
-                   ConvertModeBits::encode(convert_mode)) {}
+                   ConvertModeBits::encode(convert_mode) |
+                   TailCallModeBits::encode(tail_call_mode)) {}
 
   ExtraICState GetExtraICState() const { return bit_field_; }
 
   static void GenerateAheadOfTime(Isolate*,
                                   void (*Generate)(Isolate*,
                                                    const CallICState&));
 
   int argc() const { return ArgcBits::decode(bit_field_); }
   ConvertReceiverMode convert_mode() const {
     return ConvertModeBits::decode(bit_field_);
   }
+  TailCallMode tail_call_mode() const {
+    return TailCallModeBits::decode(bit_field_);
+  }
 
  private:
   typedef BitField<int, 0, Code::kArgumentsBits> ArgcBits;
-  typedef BitField<ConvertReceiverMode, Code::kArgumentsBits, 2>
-      ConvertModeBits;
+  typedef BitField<ConvertReceiverMode, ArgcBits::kNext, 2> ConvertModeBits;
+  typedef BitField<TailCallMode, ConvertModeBits::kNext, 1> TailCallModeBits;
 
   int const bit_field_;
 };
 
 
 std::ostream& operator<<(std::ostream& os, const CallICState& s);
 
 
 class BinaryOpICState final BASE_EMBEDDED {
  public:
@@ skipping 208 matching lines @@
                                                << LanguageModeState::kShift;
 
  private:
   const ExtraICState state_;
 };
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_IC_STATE_H_