[jdk17u-dev] RFR: 8286562: GCC 12 reports some compiler warnings

[Dan Lutker]

Clean backport to support building with GCC 12

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Commit messages:
 - Backport 410a25d59a11b6a627bbb0a2c405c2c2be19f464

Changes: https://git.openjdk.org/jdk17u-dev/pull/1087/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk17u-dev&pr=1087&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8286562
  Stats: 41 lines in 5 files changed: 26 ins; 1 del; 14 mod
  Patch: https://git.openjdk.org/jdk17u-dev/pull/1087.diff
  Fetch: git fetch https://git.openjdk.org/jdk17u-dev pull/1087/head:pull/1087

PR: https://git.openjdk.org/jdk17u-dev/pull/1087