RFR: 8371885: Mark UseCompressedClassPointers as obsolete for JDK 27

[Martin Doerr]

On Fri, 14 Nov 2025 12:52:07 GMT, Thomas Stuefe <stuefe at openjdk.org> wrote:

> Trivial patch to move the obsoletion of `UseCompressedClassPointers` to jdk 27.
> 
> Tested locally by adjusting SPECIAL_FLAG_VALIDATION_BUILD and running the `special_flags` gtest.

LGTM.

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Marked as reviewed by mdoerr (Reviewer).

PR Review: https://git.openjdk.org/jdk/pull/28322#pullrequestreview-3465005537