Revert of [snapshot] Move builtins generation into mksnapshot

src/setup-isolate.h

-// Copyright 2017 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.
-
-namespace v8 {
-namespace internal {
-
-class Builtins;
-class Code;
-class Isolate;
-
-namespace interpreter {
-class Interpreter;
-}  // namespace interpreter
-
-// This class is an abstraction layer around initialization of components
-// that are either deserialized from the snapshot or generated from scratch.
-// Currently this includes builtins and interpreter bytecode handlers.
-// There are three implementations to choose from (at link time):
-// - setup-isolate-deserialize.cc: always loads things from snapshot.
-// - setup-isolate-full.cc: always generates things.
-// - setup-isolate-for-tests.cc: does the one or the other, controlled by
-//                               the |create_heap_objects| flag.
-//
-// The actual implementations of generation of builtins and handlers is in
-// setup-builtins-internal.cc and setup-interpreter-internal.cc, and is
-// linked in by the latter two Delegate implementations.
-class SetupIsolateDelegate {
- public:
-  SetupIsolateDelegate() {}
-  virtual ~SetupIsolateDelegate() {}
-
-  virtual void SetupBuiltins(Isolate* isolate, bool create_heap_objects);
-
-  virtual void SetupInterpreter(interpreter::Interpreter* interpreter,
-                                bool create_heap_objects);
-
- protected:
-  static void SetupBuiltinsInternal(Isolate* isolate);
-  static void AddBuiltin(Builtins* builtins, int index, Code* code);
-};
-
-}  // namespace internal
-}  // namespace v8