Revert of [es6] Fix scoping for default parameters in arrow functions

src/parameter-initializer-rewriter.h

Index: src/parameter-initializer-rewriter.h
diff --git a/src/parameter-initializer-rewriter.h b/src/parameter-initializer-rewriter.h
deleted file mode 100644
index a195cb600ff7cca8e70718538d4fb4d6d8c39d61..0000000000000000000000000000000000000000
--- a/src/parameter-initializer-rewriter.h
+++ /dev/null
@@ -1,22 +0,0 @@
-// 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.
-
-#ifndef V8_PARAMETER_EXPRESSION_REWRITER_H_
-#define V8_PARAMETER_EXPRESSION_REWRITER_H_
-
-#include "src/ast.h"
-
-namespace v8 {
-namespace internal {
-
-
-void RewriteParameterInitializerScope(uintptr_t stack_limit,
-                                      Expression* initializer, Scope* old_scope,
-                                      Scope* new_scope);
-
-
-}  // namespace internal
-}  // namespace v8
-
-#endif  // V8_PARAMETER_EXPRESSION_REWRITER_H_