During the development of RoundVF/RoundF, we faced the issues which were only spotted by running test exhaustively against 32/64 bits range of int/long.
It's helpful to add these exhaustive tests in jdk for future possible usage, rather than build it everytime when needed.
Of course, we need to put it in `manual` mode, so it's not run when `-automatic` jtreg option is specified which I guess is the mode CI used, please correct me if I'm assume incorrectly.