[jdk25u] RFR: 8367313: CTW: Execute in AWT headless mode

[Aleksey Shipilev]

Improves CTW reliability.

Additional testing:
 - [x] Linux x86_64 server fastdebug, `applications/ctw/modules`

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Commit messages:
 - Backport 7e738f0d906e574706a277fabbc2cc1df6f11f19

Changes: https://git.openjdk.org/jdk25u/pull/271/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk25u&pr=271&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8367313
  Stats: 2 lines in 1 file changed: 2 ins; 0 del; 0 mod
  Patch: https://git.openjdk.org/jdk25u/pull/271.diff
  Fetch: git fetch https://git.openjdk.org/jdk25u.git pull/271/head:pull/271

PR: https://git.openjdk.org/jdk25u/pull/271