Merge topic 'cuda_add_lto_support'

96bc59b1ca CUDA: Add Device LTO support for nvcc
1527d48cd0 CheckIPO: Refactor logic selecting test source files
4a552ab4ad remove unused variables
6eda92d037 remove unused variable

Acked-by: Kitware Robot <kwrobot@kitware.com>
Merge-request: !7389