RFR: 8327945: Inline HasScavengableOops

[Albert Mingkun Yang]

Trivial inlining a class to reduce its visibility.

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Commit messages:
 - trivial

Changes: https://git.openjdk.org/jdk/pull/18223/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=18223&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8327945
  Stats: 16 lines in 1 file changed: 1 ins; 3 del; 12 mod
  Patch: https://git.openjdk.org/jdk/pull/18223.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/18223/head:pull/18223

PR: https://git.openjdk.org/jdk/pull/18223