[jdk21u-dev] RFR: 8332252: Clean up vmTestbase/vm/share

[Goetz Lindenmaier]

I backport this to make later backorts clean.

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Commit messages:
 - Backport a81e1bf1e1a6f00280b9be987c03fe20915fd52c

Changes: https://git.openjdk.org/jdk21u-dev/pull/1822/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk21u-dev&pr=1822&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8332252
  Stats: 1669 lines in 45 files changed: 27 ins; 1595 del; 47 mod
  Patch: https://git.openjdk.org/jdk21u-dev/pull/1822.diff
  Fetch: git fetch https://git.openjdk.org/jdk21u-dev.git pull/1822/head:pull/1822

PR: https://git.openjdk.org/jdk21u-dev/pull/1822