Add a basic compiler dispatcher

test/unittests/compiler-dispatcher/compiler-dispatcher-helper.h

+// Copyright 2016 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_UNITTESTS_COMPILER_DISPATCHER_COMPILER_DISPATCHER_HELPER_H_
+#define V8_UNITTESTS_COMPILER_DISPATCHER_COMPILER_DISPATCHER_HELPER_H_
+
+namespace v8 {
+
+class Isolate;
+
+namespace internal {
+
+class Object;
+template <typename T>
+class Handle;
+
+Handle<Object> RunJS(v8::Isolate* isolate, const char* script);
+
+}  // namespace internal
+}  // namespace v8
+
+#endif  // V8_UNITTESTS_COMPILER_DISPATCHER_COMPILER_DISPATCHER_HELPER_H_