RFR: 7904034: jcstress: Run with global int/C1/C2 modes even with split compilation

[Aleksey Shipilev]

WIP.

[JDK-8351997](https://bugs.openjdk.org/browse/JDK-8351997) shows there is a gap in current configuration coverage with jcstress. When split compilation is enabled, harness asks to int/C1/C2 each actor method separately. Unfortunately, there are cases in Hotspot where the barrier scheme depends on whether C2 is globally enabled. [JDK-8351997](https://bugs.openjdk.org/browse/JDK-8351997) would fail split int/C1 test with C2 globally disabled.

Therefore, harness should run with global int/C1/C2 modes even with split compilation. This complicates testing matrix quite a bit, but it should capture bugs like [JDK-8351997](https://bugs.openjdk.org/browse/JDK-8351997) more reliably.

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Commit messages:
 - Filter C2 stress options
 - Something works
 - Work

Changes: https://git.openjdk.org/jcstress/pull/168/files
  Webrev: https://webrevs.openjdk.org/?repo=jcstress&pr=168&range=00
  Issue: https://bugs.openjdk.org/browse/CODETOOLS-7904034
  Stats: 126 lines in 3 files changed: 92 ins; 12 del; 22 mod
  Patch: https://git.openjdk.org/jcstress/pull/168.diff
  Fetch: git fetch https://git.openjdk.org/jcstress.git pull/168/head:pull/168

PR: https://git.openjdk.org/jcstress/pull/168