Author: Andreas Beckmann <anbe@debian.org>
Description: add /usr/lib/cuda to CUDA search paths
 nvidia-cuda-toolkit/non-free now provides a shim monolitic cuda install
 tree in /usr/lib/cuda (LP: #1706326) that could be used for
   clang++ --cuda-path=/usr/lib/cuda

 let clang try that path by default, too, s.t. an explicit --cuda-path is
 not needed for the nvidia-cuda-toolkit/non-free packages
 
 try the new path *after* the default paths /usr/local/cuda{,-X.Y}
 to not interfere with cuda installations from nvidia's installer

--- a/clang/lib/Driver/ToolChains.cpp
+++ b/clang/lib/Driver/ToolChains.cpp
@@ -1825,6 +1825,7 @@ CudaInstallationDetector::CudaInstallati
     CudaPathCandidates.push_back(D.SysRoot + "/usr/local/cuda");
     for (const char *Ver : Versions)
       CudaPathCandidates.push_back(D.SysRoot + "/usr/local/cuda-" + Ver);
+    CudaPathCandidates.push_back(D.SysRoot + "/usr/lib/cuda");
   }
 
   for (const auto &CudaPath : CudaPathCandidates) {