RFR: 8367739: Serial: Retry allocation after lock acquire in mem_allocate_work

Wed Sep 17 10:54:09 UTC 2025

Restoring the allocation retrying logic inside lock-region to avoid premature GCs. This logic was mistakenly removed in [JDK-8364628](https://bugs.openjdk.org/browse/JDK-8364628).

Test: tier1-3

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Commit messages:
 - sgc-retry

Changes: https://git.openjdk.org/jdk/pull/27340/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=27340&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8367739
  Stats: 39 lines in 2 files changed: 28 ins; 10 del; 1 mod
  Patch: https://git.openjdk.org/jdk/pull/27340.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/27340/head:pull/27340

PR: https://git.openjdk.org/jdk/pull/27340