RFR: 8321688: Build on linux with GCC 7.5.0 fails after 8319577

[Guoxiong Li]

Hi all,

This patch fixes the building failure introduced by [JDK-8319577](https://bugs.openjdk.org/browse/JDK-8319577) in old GCC version (linux & GCC 7.5.0 locally).

Thanks for the review.

 Best Regards,
-- Guoxiong

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Commit messages:
 - JDK-8321688

Changes: https://git.openjdk.org/jdk/pull/17047/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=17047&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8321688
  Stats: 4 lines in 2 files changed: 0 ins; 2 del; 2 mod
  Patch: https://git.openjdk.org/jdk/pull/17047.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/17047/head:pull/17047

PR: https://git.openjdk.org/jdk/pull/17047