RFR: 8360405: [PPC64] some environments don't support mfdscr instruction [v2]

[Martin Doerr]

> See https://github.com/openjdk/jdk/pull/20262#issuecomment-2999872960

Martin Doerr has updated the pull request incrementally with one additional commit since the last revision:

  Add comment.

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Changes:
  - all: https://git.openjdk.org/jdk/pull/25953/files
  - new: https://git.openjdk.org/jdk/pull/25953/files/48d7cc95..d7f1c1d8

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=25953&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=25953&range=00-01

  Stats: 3 lines in 1 file changed: 0 ins; 0 del; 3 mod
  Patch: https://git.openjdk.org/jdk/pull/25953.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/25953/head:pull/25953

PR: https://git.openjdk.org/jdk/pull/25953