[jdk17u] RFR: 8270094: Shenandoah: Provide human-readable labels for test configurations

[Aleksey Shipilev]

Clean backport to improve testing UX.

Additional testing:
 - [x] hotspot_gc_shenandoah passes

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

Commit messages:
 - Backport 676f1d76cab9108655f2ce462db321b975563eb7

Changes: https://git.openjdk.java.net/jdk17u/pull/29/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk17u&pr=29&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8270094
  Stats: 227 lines in 81 files changed: 19 ins; 0 del; 208 mod
  Patch: https://git.openjdk.java.net/jdk17u/pull/29.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk17u pull/29/head:pull/29

PR: https://git.openjdk.java.net/jdk17u/pull/29