RFR: 7903535: JOL: Show array base improvements in heapdump-estimates

[Aleksey Shipilev]

This would help to ballpark the improvements from [JDK-8139457](https://bugs.openjdk.org/browse/JDK-8139457).

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Commit messages:
 - Work

Changes: https://git.openjdk.org/jol/pull/50/files
 Webrev: https://webrevs.openjdk.org/?repo=jol&pr=50&range=00
  Issue: https://bugs.openjdk.org/browse/CODETOOLS-7903535
  Stats: 314 lines in 8 files changed: 36 ins; 183 del; 95 mod
  Patch: https://git.openjdk.org/jol/pull/50.diff
  Fetch: git fetch https://git.openjdk.org/jol.git pull/50/head:pull/50

PR: https://git.openjdk.org/jol/pull/50