Add a preview feature for the NR jep, other stylistic cleanup -------------
Commit messages: - Minor cleanup, preview and since Changes: https://git.openjdk.org/valhalla/pull/1927/files Webrev: https://webrevs.openjdk.org/?repo=valhalla&pr=1927&range=00 Stats: 15 lines in 4 files changed: 8 ins; 2 del; 5 mod Patch: https://git.openjdk.org/valhalla/pull/1927.diff Fetch: git fetch https://git.openjdk.org/valhalla.git pull/1927/head:pull/1927 PR: https://git.openjdk.org/valhalla/pull/1927
