Connor Abbott authored Feb 03, 2020 and Jonathan Marek committed Feb 12, 2020

This has only lightly been tested. It passes dEQP-VK.api.smoke.triangle,
so at least we're able to show a triangle. For now, it's just enabled
under a debug flag. In the future we'll probably want some heuristics
like what freedreno has and another debug flag to disable it except when
it's forced.

Part-of: <mesa/mesa!3713>