RFR: 8358003: KlassTrainingData initializer reads garbage holder [v2]

[Igor Veresov]

> Simplify KlassTrainingData constructor. The lines in question come from the old pre-CDS world. They are not needed anymore.

Igor Veresov has updated the pull request incrementally with one additional commit since the last revision:

  No need for release_store()

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Changes:
  - all: https://git.openjdk.org/jdk/pull/25623/files
  - new: https://git.openjdk.org/jdk/pull/25623/files/f9b133fe..85a71619

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=25623&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=25623&range=00-01

  Stats: 2 lines in 1 file changed: 0 ins; 0 del; 2 mod
  Patch: https://git.openjdk.org/jdk/pull/25623.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/25623/head:pull/25623

PR: https://git.openjdk.org/jdk/pull/25623