[jfx24u] RFR: 8351653: Webkit debug build failure after update to 620.1

[Jay Bhaskar]

A clean backport to jfx24u. This fixes debug build error on mac platform.

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Commit messages:
 - Backport 99ee34fe6f82dddc554a32d09e88b9e43329045e

Changes: https://git.openjdk.org/jfx24u/pull/13/files
  Webrev: https://webrevs.openjdk.org/?repo=jfx24u&pr=13&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8351653
  Stats: 3 lines in 1 file changed: 0 ins; 0 del; 3 mod
  Patch: https://git.openjdk.org/jfx24u/pull/13.diff
  Fetch: git fetch https://git.openjdk.org/jfx24u.git pull/13/head:pull/13

PR: https://git.openjdk.org/jfx24u/pull/13