Specular masked by shadows - 2 problems at once

Hello!

It seems I have stumbled upon a bug while investigating another issue.

First off, I'm really finding the option "Mask directional light specular by shadows" to output terrible results. But I'm not going to report it since I haven't done a lot of investigating on the issue. Simple scenes with default lighting already show the issue, it should be super easy to find, really. I'm with Unity 5.5.0p4.

BUT, the real issue is that the checkbox doesn't show it's checked, and is greyed out unless the forward rendering path is chosen. If you uncheck it, the issue is gone back in deferred. So I'm thinking either the checkbox should stay interactive, or perhaps simply showing the right value could be a start.

Let me know, but in the meantime, I can go around it.

Cheers!