[jdk18u] RFR: 8284023: java.sun.awt.X11GraphicsDevice.getDoubleBufferVisuals() leaks XdbeScreenVisualInfo

[Zhengyu Gu]

A clean, low risk backport to fix a memory leak.

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Commit messages:
 - Backport ec205f68a883cef6b98f26a06baf675f7da26928

Changes: https://git.openjdk.java.net/jdk18u/pull/105/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk18u&pr=105&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8284023
  Stats: 3 lines in 1 file changed: 3 ins; 0 del; 0 mod
  Patch: https://git.openjdk.java.net/jdk18u/pull/105.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk18u pull/105/head:pull/105

PR: https://git.openjdk.java.net/jdk18u/pull/105