Enable CUDA build on Windows in AppVeyor.

appveyor.yml

@@ -4,6 +4,7 @@ environment:
       LLVM_VERSION: 6.0.1
       LLVM_VERSION_SHORT: 60
       VS_MAJOR_VERSION: 14
+      USE_CUDA: 1
     - APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2015
       LLVM_VERSION: 5.0.2
       LLVM_VERSION_SHORT: 50
@@ -34,9 +35,9 @@ install:
   - 7z x LuaJIT-2.0.5.zip
   - set LUAJIT_DIR=%CD%\LuaJit-2.0.5
 
-  # - appveyor DownloadFile  https://developer.nvidia.com/compute/cuda/8.0/prod/local_installers/cuda_8.0.44_windows-exe -FileName cuda_8.0.44_windows.exe
-  # - cuda_8.0.44_windows.exe -s compiler_8.0 cublas_8.0 cublas_dev_8.0 cudart_8.0 curand_8.0 curand_dev_8.0
-  # - set CUDA_DIR=C:\Program Files\NVIDIA GPU Computing Toolkit\CUDA\v8.0
+  - if /I "%USE_CUDA%" EQU "1" (appveyor DownloadFile https://developer.nvidia.com/compute/cuda/9.2/Prod2/local_installers2/cuda_9.2.148_windows -FileName cuda.exe)
+  - if /I "%USE_CUDA%" EQU "1" (.\cuda -s nvcc_9.2 cudart_9.2)
+  - if /I "%USE_CUDA%" EQU "1" (set CUDA_DIR=C:\Program Files\NVIDIA GPU Computing Toolkit\CUDA\v9.2)
 
   - set TERRA_DIR=%CD%
   - dir