NVIDIA have released driver 390.77, and details are here:  http://www.nvidia.com/Download/driverResults.aspx/136120/en-us

I have tested this with Kernel 4.18-rc5, and it compiles/loads successfully:

......................................
ld -r -o /home/rgadsdon/kernel/NVIDIA-Linux-x86_64-390.77/kernel/nvidia-modeset/nv-modeset-interface.o /home/rgadsdon/kernel/NVIDIA-Linux-x86_64-390.77/kernel/nvidia-modeset/nvidia-modeset-linux.o
Building modules, stage 2.
MODPOST 4 modules
CC /home/rgadsdon/kernel/NVIDIA-Linux-x86_64-390.77/kernel/nvidia-drm.mod.o
LD [M] /home/rgadsdon/kernel/NVIDIA-Linux-x86_64-390.77/kernel/nvidia-drm.ko
CC /home/rgadsdon/kernel/NVIDIA-Linux-x86_64-390.77/kernel/nvidia-modeset.mod.o
LD [M] /home/rgadsdon/kernel/NVIDIA-Linux-x86_64-390.77/kernel/nvidia-modeset.ko
CC /home/rgadsdon/kernel/NVIDIA-Linux-x86_64-390.77/kernel/nvidia-uvm.mod.o
LD [M] /home/rgadsdon/kernel/NVIDIA-Linux-x86_64-390.77/kernel/nvidia-uvm.ko
CC /home/rgadsdon/kernel/NVIDIA-Linux-x86_64-390.77/kernel/nvidia.mod.o
LD [M] /home/rgadsdon/kernel/NVIDIA-Linux-x86_64-390.77/kernel/nvidia.ko
make[2]: Leaving directory '/usr/src/linux-4.18-rc5'
make[1]: Leaving directory '/usr/src/linux-4.18-rc5'

Robert Gadsdon.   July 16, 2018