RFR: 8290023: Remove use of IgnoreUnrecognizedVMOptions in gc tests [v2]

[Thomas Schatzl]

> Hi all,
> 
>   can I have reviews for removal of the use of `-XX:+IgnoreUnrecognizedVMOptions` for gc tests?
> 
> As per [JDK-8228493](https://bugs.openjdk.org/browse/JDK-8228493) use of that option has drawbacks wrt to test reliability, so trying to remove them by
> * duplicating `@test` blocks (mostly sme Shenandoah tests as I could not find a good way for them)
> * adding additional `@requires`
> * removing it in tests where it is not actually required
> 
> Testing: gha, running tests
> 
> Thanks,
>   Thomas

Thomas Schatzl has updated the pull request incrementally with one additional commit since the last revision:

  ayang, kbarrett review

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/9443/files
  - new: https://git.openjdk.org/jdk/pull/9443/files/9848697e..279b99d9

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=9443&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=9443&range=00-01

  Stats: 36 lines in 6 files changed: 2 ins; 11 del; 23 mod
  Patch: https://git.openjdk.org/jdk/pull/9443.diff
  Fetch: git fetch https://git.openjdk.org/jdk pull/9443/head:pull/9443

PR: https://git.openjdk.org/jdk/pull/9443