RFR: 8328592: hprof tests fail with -XX:-CompactStrings [v3]

[Aleksey Shipilev]

> See the bug for symptoms. The tests are failing because hprof test library is confused about non-compact strings.
> 
> Additional testing:
>  - [x] `serviceability/HeapDump lib-test:all` with `-XX:-CompactStrings` now pass
>  - [x]  `serviceability/HeapDump lib-test:all` with `-XX:+CompactStrings` still pass

Aleksey Shipilev has updated the pull request incrementally with one additional commit since the last revision:

  Copyright years

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/18394/files
  - new: https://git.openjdk.org/jdk/pull/18394/files/f783418d..6c677007

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=18394&range=02
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=18394&range=01-02

  Stats: 2 lines in 2 files changed: 0 ins; 0 del; 2 mod
  Patch: https://git.openjdk.org/jdk/pull/18394.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/18394/head:pull/18394

PR: https://git.openjdk.org/jdk/pull/18394