[CUDA] Fix nvidia-cuda-toolkit detection on Ubuntu

This just extends D40453 (r319317) to Ubuntu.

Reviewed By: Hahnfeld, tra

Differential Revision: https://reviews.llvm.org/D55269

llvm-svn: 348504
diff --git a/clang/lib/Driver/ToolChains/Cuda.cpp b/clang/lib/Driver/ToolChains/Cuda.cpp
index b298617..a8363b2 100644
--- a/clang/lib/Driver/ToolChains/Cuda.cpp
+++ b/clang/lib/Driver/ToolChains/Cuda.cpp
@@ -114,7 +114,7 @@
     for (const char *Ver : Versions)
       Candidates.emplace_back(D.SysRoot + "/usr/local/cuda-" + Ver);
 
-    if (Distro(D.getVFS()).IsDebian())
+    if (Distro(D.getVFS()).IsDebian() || Distro(D.getVFS()).IsUbuntu())
       // Special case for Debian to have nvidia-cuda-toolkit work
       // out of the box. More info on http://bugs.debian.org/882505
       Candidates.emplace_back(D.SysRoot + "/usr/lib/cuda");