Win7 X64, vega 64 with 17.9.3, 1080TI with 385.69,
Broken: latest master
Short description of error
When cycles is compiled with cubins and an nvidia card is installed, OpenCL is not available in user pref anymore. If it's compiled without cubins, then the OpenCL option is available.
Exact steps for others to reproduce the error
On a PC with windows, and both an AMD and Nvidia card compatible with current cycles and a display connected to them:
compile Blender with "make.bat full", start it : OpenCL option is available.
compile Blender with "make.bat release": only CUDA is available.