RFR: 8353185: Introduce the concept of upgradeable files in context of JEP 493 [v5]

[Severin Gehwolf]

> For JEP 493-enabled builds there are no JMODs. Certain files come from the installed JDK image when a user creates a custom run-time from it. This is problematic for example for files that often come from a different package (e.g. `cacerts` file for Linux distro builds of OpenJDK packaged as RPMs), or more generally when they get updated out-of-band of the JDK build itself like the tzupdater tool.
> 
> When that happens the hash sum recorded at JDK build time of those files no longer match, causing `jlink` to fail. I propose to allow for those files to get "upgraded" should this happen. The way this works is as follows:
> 
> 1. The list of upgradeable files is configured by a resource file in `jdk.jlink` on a per module basis. Right now, only two files from the `java.base` module will be allowed to be upgraded with a link from the current run-time image.
> 2. For those files the hash sum checks are skipped.
> 
> **Testing**
> 
> - [x] GHA
> - [x] `jdk/tools/jlink` jtreg tests (also on [GHA](https://github.com/jerboaa/jdk/actions/runs/14308729271))
> - [x] Some manual tests with updated `tzdb.dat` and `cacerts` files.
> 
> Thoughts?

Severin Gehwolf has updated the pull request incrementally with one additional commit since the last revision:

  Use *.conf for upgrade files

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/24388/files
  - new: https://git.openjdk.org/jdk/pull/24388/files/89d3886d..4434c78e

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=24388&range=04
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=24388&range=03-04

  Stats: 11 lines in 4 files changed: 6 ins; 3 del; 2 mod
  Patch: https://git.openjdk.org/jdk/pull/24388.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/24388/head:pull/24388

PR: https://git.openjdk.org/jdk/pull/24388