Create ast/ and parsing/ subdirectories and move appropriate files

src/ast-numbering.h

-// 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.
-
-#ifndef V8_AST_NUMBERING_H_
-#define V8_AST_NUMBERING_H_
-
-namespace v8 {
-namespace internal {
-
-// Forward declarations.
-class FunctionLiteral;
-class Isolate;
-class Zone;
-
-namespace AstNumbering {
-// Assign type feedback IDs and bailout IDs to an AST node tree.
-//
-bool Renumber(Isolate* isolate, Zone* zone, FunctionLiteral* function);
-}
-
-}  // namespace internal
-}  // namespace v8
-
-#endif  // V8_AST_NUMBERING_H_