Monobevaiour script is invoked even if there is no object attached.

Script's Awake, OnEnable, OnDisable functions are invoked when I select a prefab containing script and SpriteRenderer at playing the editor.
The function is called by GUIUtility:: ProcessEvent.

Bug recurring step:
1. Create new project
2. Create a script and add log on Awake.
3. Create a prefab and attach a SpriteRenderer and the script.
4. Assign SpriteRenderer's sprite field to any sprite.
5. Create a empty scene.
6. Select the prefab and play the editor.
7. Then you can see the log.

I attached the project.

I am using 2D Experimental Preview 4 Updated May 11th 2017.
I checked Unity 5.6.0f3 version has no problem with this issue.

Thank you.