[jdk17u-dev] RFR: 8271825: mark hotspot runtime/LoadClass tests which ignore external VM flags

[Goetz Lindenmaier]

I backport this to improve testing in 17.

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Commit messages:
 - Backport 68f784778ce24a26d768b62b979fd587f131d332

Changes: https://git.openjdk.org/jdk17u-dev/pull/2934/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk17u-dev&pr=2934&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8271825
  Stats: 5 lines in 3 files changed: 3 ins; 0 del; 2 mod
  Patch: https://git.openjdk.org/jdk17u-dev/pull/2934.diff
  Fetch: git fetch https://git.openjdk.org/jdk17u-dev.git pull/2934/head:pull/2934

PR: https://git.openjdk.org/jdk17u-dev/pull/2934