Add some additional and more fine-grained way in which custom makefiles can be integrated.
------------- Commit messages: - Missed hook for cleaning - Turns out these were needed after all... - 8361142: Improve custom hooks for makefiles Changes: https://git.openjdk.org/jdk/pull/26060/files Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=26060&range=00 Issue: https://bugs.openjdk.org/browse/JDK-8361142 Stats: 38 lines in 8 files changed: 24 ins; 0 del; 14 mod Patch: https://git.openjdk.org/jdk/pull/26060.diff Fetch: git fetch https://git.openjdk.org/jdk.git pull/26060/head:pull/26060 PR: https://git.openjdk.org/jdk/pull/26060
