RFR: 8321075: RISC-V: UseSystemMemoryBarrier lacking proper OS support

[Robbin Ehn]

Hi, please consider.

RV port was pickup into mainline Linux 4.4.
The same version also made membar private expedited mandatory, but this was missed in RV port.
This means to we need to check kernel version in runtime to figure out if it's usable.

Kernel fix is here:
https://git.kernel.org/pub/scm/linux/kernel/git/palmer/linux.git/commit/?h=for-next&id=0420af54c2c2b7b3abbd986a41aded7cab0137ef

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

Commit messages:
 - Added runtime kernel version check

Changes: https://git.openjdk.org/jdk/pull/17889/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=17889&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8321075
  Stats: 40 lines in 3 files changed: 39 ins; 0 del; 1 mod
  Patch: https://git.openjdk.org/jdk/pull/17889.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/17889/head:pull/17889

PR: https://git.openjdk.org/jdk/pull/17889