RFR: 8318363: Foreign benchmarks fail to build on some platforms

[Aleksey Shipilev]

Recent regression, see bug. The fix is to use the proper `jlong <-> ptr` converters.

Additional testing:
 - [x] Build now passes on ARM32
 - [x] Two affected JMH benchmarks still run

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Commit messages:
 - Fix

Changes: https://git.openjdk.org/jdk/pull/16228/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=16228&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8318363
  Stats: 4 lines in 2 files changed: 2 ins; 0 del; 2 mod
  Patch: https://git.openjdk.org/jdk/pull/16228.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/16228/head:pull/16228

PR: https://git.openjdk.org/jdk/pull/16228