System Information
Operating system: Windows 10 1809
Graphics card: GTX 1070

Blender Version
Broken: 2.80, 80ffa73b3f87, blender2.8, 2019-01-10, as found on the splash screen

Short description of error
Normal maps in DDS files with this compression method do not get loaded or rendered correctly.

Exact steps for others to reproduce the error
Download attached ZIP.
In the scene there are 3 cubes with the same normal map, but exported in different ways (PNG, DDS BC3 and DDS BC5).
You will notice that the last one is not loaded correctly or at all.

The DDS were exported from Photoshop using the Intel Texture Tools plugin.
The plugin states that this compression method only uses the first two channels, and is optimized for normal maps (in-game in fact this method reduces the compression artifacts while maintaining a good file size)