[jfx24u] RFR: 8354336: gstclock.c: compilation error: 'incompatible pointer type' with gcc 14

[Alexander Matveev]

Clean backport of JDK-8354336.

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Commit messages:
 - Backport 3fdd21386d6db96294fcecd80afc25d09732c067

Changes: https://git.openjdk.org/jfx24u/pull/26/files
  Webrev: https://webrevs.openjdk.org/?repo=jfx24u&pr=26&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8354336
  Stats: 7 lines in 2 files changed: 4 ins; 0 del; 3 mod
  Patch: https://git.openjdk.org/jfx24u/pull/26.diff
  Fetch: git fetch https://git.openjdk.org/jfx24u.git pull/26/head:pull/26

PR: https://git.openjdk.org/jfx24u/pull/26