[jdk21u-dev] RFR: 8316451: 6 java/lang/instrument/PremainClass tests ignore VM flags

[Goetz Lindenmaier]

I backport this for parity with 21.0.4-oracle.

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Commit messages:
 - Backport 9029bf644e238a504e1f114a73edf5760d19980b

Changes: https://git.openjdk.org/jdk21u-dev/pull/463/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk21u-dev&pr=463&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8316451
  Stats: 10 lines in 2 files changed: 0 ins; 4 del; 6 mod
  Patch: https://git.openjdk.org/jdk21u-dev/pull/463.diff
  Fetch: git fetch https://git.openjdk.org/jdk21u-dev.git pull/463/head:pull/463

PR: https://git.openjdk.org/jdk21u-dev/pull/463