RFR: 8364541: Parallel: Support allocation in old generation when heap is almost full

Fri Aug 1 15:42:06 UTC 2025

Adding old-gen allocation support in heap-almost-full scenario. This can make tests that cause OOM deliberately more resilient to timeout and help runaway apps to exit/fail faster.

Test: tier1-3

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Commit messages:
 - pgc-old-gen-allocate

Changes: https://git.openjdk.org/jdk/pull/26599/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=26599&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8364541
  Stats: 7 lines in 1 file changed: 2 ins; 0 del; 5 mod
  Patch: https://git.openjdk.org/jdk/pull/26599.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/26599/head:pull/26599

PR: https://git.openjdk.org/jdk/pull/26599