RFR: 8338248: PartialArrayStateAllocator::Impl leaks Arena array

[Zhengyu Gu]

Simple fix for a memory leak

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Commit messages:
 - 8338248: PartialArrayStateAllocator::Impl leaks Arena array

Changes: https://git.openjdk.org/jdk/pull/20557/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=20557&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8338248
  Stats: 2 lines in 1 file changed: 2 ins; 0 del; 0 mod
  Patch: https://git.openjdk.org/jdk/pull/20557.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/20557/head:pull/20557

PR: https://git.openjdk.org/jdk/pull/20557