cmake OSVR_HAS_STD_MAKE_UNIQUE examples

OSVR/SteamVR-OSVR src/CMakeLists.txt :21

check_cxx_source_compiles("#include <memory>\nint main(int, char**) { std::unique_ptr<int> i = std::make_unique<int>(0); }" OSVR_HAS_STD_MAKE_UNIQUE)