RFR: 8334695: Fix build failure without zgc after JDK-8333300

[Jie Fu]

Hi all,

The patch fixes the build failure without zgc.
Please review.

Thanks.
Best regards,
Jie

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Commit messages:
 - 8334695: Fix build failure without zgc after JDK-8333300

Changes: https://git.openjdk.org/jdk/pull/19818/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=19818&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8334695
  Stats: 10 lines in 4 files changed: 6 ins; 0 del; 4 mod
  Patch: https://git.openjdk.org/jdk/pull/19818.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/19818/head:pull/19818

PR: https://git.openjdk.org/jdk/pull/19818