[es6] Tail calls support.

src/compiler/js-operator.h

 // Copyright 2013 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_COMPILER_JS_OPERATOR_H_
 #define V8_COMPILER_JS_OPERATOR_H_
 
 #include "src/compiler/type-hints.h"
 #include "src/runtime/runtime.h"
 
@@ skipping 33 matching lines @@
 
 
 // The ConvertReceiverMode is used as parameter by JSConvertReceiver operators.
 ConvertReceiverMode ConvertReceiverModeOf(Operator const* op);
 
 
 // The ToBooleanHints are used as parameter by JSToBoolean operators.
 ToBooleanHints ToBooleanHintsOf(Operator const* op);
 
 
-// Defines whether tail call optimization is allowed.
-enum class TailCallMode : unsigned { kAllow, kDisallow };
-
-size_t hash_value(TailCallMode);
-
-std::ostream& operator<<(std::ostream&, TailCallMode);
-
-
 // Defines the language mode and hints for a JavaScript binary operations.
 // This is used as parameter by JSAdd, JSSubtract, etc. operators.
 class BinaryOperationParameters final {
  public:
   BinaryOperationParameters(LanguageMode language_mode,
                             BinaryOperationHints hints)
       : language_mode_(language_mode), hints_(hints) {}
 
   LanguageMode language_mode() const { return language_mode_; }
   BinaryOperationHints hints() const { return hints_; }
@@ skipping 516 matching lines @@
   Zone* const zone_;
 
   DISALLOW_COPY_AND_ASSIGN(JSOperatorBuilder);
 };
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_COMPILER_JS_OPERATOR_H_