RFR: 8330266: RISC-V: Restore frm to RoundingMode::rne after JNI [v2]

[Hamlin Li]

> Hi,
> Can you help to review this patch?
> As discussed at: https://github.com/openjdk/jdk/pull/18758#pullrequestreview-1999982333, we'd better to do it.
> Similar thing is done on aarch64, https://bugs.openjdk.org/browse/JDK-8320892
> 
> Thanks

Hamlin Li has updated the pull request incrementally with one additional commit since the last revision:

  refine code

-------------

Changes:
  - all: https://git.openjdk.org/jdk/pull/18785/files
  - new: https://git.openjdk.org/jdk/pull/18785/files/096bd0de..59a488d7

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=18785&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=18785&range=00-01

  Stats: 9 lines in 5 files changed: 1 ins; 1 del; 7 mod
  Patch: https://git.openjdk.org/jdk/pull/18785.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/18785/head:pull/18785

PR: https://git.openjdk.org/jdk/pull/18785