RFR: 8345573: Module dependencies not resolved from run-time image when --limit-module is being used [v4]

[Severin Gehwolf]

> Please review this fix for JEP 493 enabled JDKs related to the `--limit-modules` option. The existing jlink `bindservices` tests cover this issue. Previously they didn't run on a JEP 493 enabled JDK, since `jmods` folder is missing for them.
> 
> The gist of the issue is that multiple `ModuleFinder`s were at play. In particular, when linking from the run-time image a finder is being set up based solely on the module-path. Which in that case only contains the application modules (not the JDK dependencies). So if the `--limit-modules` clause included any JDK modules that the app needs as a dependency the finder would fail because the module specified in the `--limit-modules` clause didn't exist in the finder's look-up space.
> 
> [A similar case happens](https://bugs.openjdk.org/browse/JDK-8345573?focusedId=14729247&page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel#comment-14729247) for a regular JDK build where `ALL-MODULE-PATH` is being used together with `--limit-modules`. In that case, the `FindException` is being thrown when the `root` set of modules are attempted to get assembled.
> 
> The fix that I'm proposing here is two fold:
> 
> 1. Distinguish whether or not we ought to resolve the JDK modules from the run-time image or not.
> 2. Based on that information set up the finders as appropriate and use the same finders when assembling the module root set.
> 
> I think this makes for a cleaner implementation and also fixes the `--limit-modules` issue when linking from the run-time image as any finder that is being limited has already been properly set up to include dependencies (if need be).
> 
> Testing:
> 
> - [x]  GHA
> - [x] jlink tests in `test/jdk/tools/jlink` on a regular JDK build and on a build with `--enable-linkable-runtime`. Both test runs show all tests passing.
> 
> Thoughts?

Severin Gehwolf has updated the pull request incrementally with three additional commits since the last revision:

 - Remove too strong assertion
 - Test fixes
 - Address comments from Mandy

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/22609/files
  - new: https://git.openjdk.org/jdk/pull/22609/files/d097e63f..73a909e8

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=22609&range=03
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=22609&range=02-03

  Stats: 177 lines in 5 files changed: 56 ins; 65 del; 56 mod
  Patch: https://git.openjdk.org/jdk/pull/22609.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/22609/head:pull/22609

PR: https://git.openjdk.org/jdk/pull/22609