[snapshot] Move builtins generation into mksnapshot

test/cctest/setup-isolate-for-tests.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.
+
+#include "src/setup-isolate.h"
+
+namespace v8 {
+namespace internal {
+
+class SetupIsolateDelegateForTests : public SetupIsolateDelegate {
+ public:
+  SetupIsolateDelegateForTests() : SetupIsolateDelegate() {}
+  virtual ~SetupIsolateDelegateForTests() {}
+
+  void SetupBuiltins(Isolate* isolate, bool create_heap_objects) override;
+
+  void SetupInterpreter(interpreter::Interpreter* interpreter,
+                        bool create_heap_objects) override;
+};
+
+}  // namespace internal
+}  // namespace v8