I am not a developer but rather an end user with a good bit of troubleshooting experience.
This is in reference to the post below that I cannot reply to since I'm not a developer.
I wanted to add that I am experiencing this same issue with Blender 2.77 specifically with the two most recent drivers on the site (listed below) when rendering GPU.
Rolling back to the driver included with 16.5.1 gives me rendering functionality back as before. I'll note the BMW render as what I used for you to reproduce the issue.
I am also choosing the Pitcairn OpenCL option in Blender with the Cycles engine. My card is a HD 7850. I'll add that another symptom I see is losing video to my monitor altogether after upgrading to either of those two driver versions. I also lose video on a reboot once Windows 10 completes booting up. This can be recovered in both scenarios by either cycling the power on the monitor OR toggling off of DisplayPort and then back to it with the input button.
It seems this has been reproduced by your team. I just wanted to add additional detail that I didn't see mentioned.
Thanks for your additional inputs. As I've any update regarding the issue, I'll share on that referred Blender cycle thread.
I've one suggestion though. If you want to share any input or have any query regarding a forum post/thread, we encourage to comment on that thread itself. It helps us (and all the users who are following that thread) to track and get all the related information from the same thread itself.