[jdk17u-dev] RFR: 8268974: GetJREPath() JLI function fails to locate libjava.so if not standard Java launcher is used

[Sergey Nazarkin]

I'd like to backport this changes as it fixes some custom launchers issue.  Fix applies cleanly. 

The functionality was tested with the new test and manually

    cd ~/tools/bin
    cp -r ~/jdk .
    cp jdk/bin/java jdk/lib
    jdk/lib/java -version


Without the patch JVM can't start

Error: could not find libjava.so
Error: Could not find Java SE Runtime Environment.

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Commit messages:
 - Backport 984003d5c969443abae2d889e92cba30da26e55f

Changes: https://git.openjdk.org/jdk17u-dev/pull/2257/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk17u-dev&pr=2257&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8268974
  Stats: 65 lines in 2 files changed: 58 ins; 1 del; 6 mod
  Patch: https://git.openjdk.org/jdk17u-dev/pull/2257.diff
  Fetch: git fetch https://git.openjdk.org/jdk17u-dev.git pull/2257/head:pull/2257

PR: https://git.openjdk.org/jdk17u-dev/pull/2257