A few changes to the build system is needed for the GHA rewrite ([JDK-8287906](https://bugs.openjdk.org/browse/JDK-8287906)).
------------- Commit messages: - 8288195: Prepare build system for GHA changes Changes: https://git.openjdk.org/jdk/pull/9122/files Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=9122&range=00 Issue: https://bugs.openjdk.org/browse/JDK-8288195 Stats: 28 lines in 3 files changed: 13 ins; 0 del; 15 mod Patch: https://git.openjdk.org/jdk/pull/9122.diff Fetch: git fetch https://git.openjdk.org/jdk pull/9122/head:pull/9122 PR: https://git.openjdk.org/jdk/pull/9122
