RFR: 8288754: GCC 12 fails to build zReferenceProcessor.cpp

[Aleksey Shipilev]

When compiling with GCC 12.1.1 (current in Fedora rawhide), the following warning-as-error is produced and breaks the build by default:

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Commit messages:
 - Fix

Changes: https://git.openjdk.org/jdk/pull/9219/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=9219&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8288754
  Stats: 1 line in 1 file changed: 0 ins; 0 del; 1 mod
  Patch: https://git.openjdk.org/jdk/pull/9219.diff
  Fetch: git fetch https://git.openjdk.org/jdk pull/9219/head:pull/9219

PR: https://git.openjdk.org/jdk/pull/9219