RFR: 8246325: Add DRYRUN facility to SetupExecute

Tue Sep 9 08:26:48 UTC 2025

With `DRYRUN := true`, the actual command line will not be executed, but all other steps are done, to facilitate debugging. 

This PR has effects on some closed Oracle code, hence the changes in the mac bundle path logic.

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Commit messages:
 - Add tests for DRYRUN
 - 8246325: Add DRYRUN facility to SetupExecute

Changes: https://git.openjdk.org/jdk/pull/27121/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=27121&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8246325
  Stats: 46 lines in 4 files changed: 34 ins; 0 del; 12 mod
  Patch: https://git.openjdk.org/jdk/pull/27121.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/27121/head:pull/27121

PR: https://git.openjdk.org/jdk/pull/27121