[jdk25] RFR: 8360405: [PPC64] some environments don't support mfdscr instruction

[Hao Sun]

On Wed, 25 Jun 2025 09:08:38 GMT, Martin Doerr <mdoerr at openjdk.org> wrote:

> Clean backport of [JDK-8360405](https://bugs.openjdk.org/browse/JDK-8360405).

Thanks for your fix.

As I tested with jdk25 branch in my environment(QEMU), it failed to run `java -version` before this PR, and it can pass with this PR.

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

Marked as reviewed by haosun (Committer).

PR Review: https://git.openjdk.org/jdk/pull/25972#pullrequestreview-2958221350