V2.80, 490a385c8124, 2018-03-02
When creating a material with an image texture and with a different colour on the back side of the object, using a png file with transparency, it does not render with Device setting 'GPU Compute'. The viewports show the object with the correct texture and render but in the render window the object, with the front and back different colours, renders black. When switching to CPU then the render is correct. This exact same setup works in V2.79b
I attached a test file which demonstrates this. I also attached the exact png image I used for this test. The renderings I attached was made with the CPU, the red is the front and the blue is the back face of the object.
The black object is rendered from the back face with the GPU Compute settings, which demonstrates the problem.