[jdk18u] RFR: 8284956: Potential leak awtImageData/color_data when initializes X11GraphicsEnvironment

[Zhengyu Gu]

A clean backport to fix memory leaks.

-------------

Commit messages:
 - Backport cbe7e7bd7f7e7ea9f7221ef206917c58baff7696

Changes: https://git.openjdk.java.net/jdk18u/pull/149/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk18u&pr=149&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8284956
  Stats: 42 lines in 1 file changed: 31 ins; 4 del; 7 mod
  Patch: https://git.openjdk.java.net/jdk18u/pull/149.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk18u pull/149/head:pull/149

PR: https://git.openjdk.java.net/jdk18u/pull/149