Eliminate FindCUDA cmake warning.
diff --git a/CMakeLists.txt b/CMakeLists.txt
index 8477d81..314c72f 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -14,6 +14,15 @@
endif (NOT DEFINED CMAKE_EXPORT_PACKAGE_REGISTRY)
endif (POLICY CMP0090)
+# Disable warning about find_package(CUDA).
+# CUDA language support is lacking for clang as the CUDA compiler
+# until at least cmake version 3.18. Even then, there seems to be
+# issues on Windows+Ninja in passing build flags. Continue using
+# the "old" way for now.
+if (POLICY CMP0146)
+ cmake_policy(SET CMP0146 OLD)
+endif ()
+
project(Eigen3)
# Remove this block after bumping CMake to v3.21.0
