RFR: 8325438: Add exhaustive tests for Math.round intrinsics

[Hamlin Li]

HI,
Can you have a look at this patch adding some tests for Math.round instrinsics?
Thanks!

### FYI:
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.

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Commit messages:
 - Initial commit

Changes: https://git.openjdk.org/jdk/pull/17753/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=17753&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8325438
  Stats: 238 lines in 2 files changed: 238 ins; 0 del; 0 mod
  Patch: https://git.openjdk.org/jdk/pull/17753.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/17753/head:pull/17753

PR: https://git.openjdk.org/jdk/pull/17753