[jdk11u-dev] RFR: 8252530: Fix inconsistencies in hotspot whitebox

[Goetz Lindenmaier]

I backport this for parity with 11.0.21-oracle.

I had to resolve because isC2OrJVMCIIncludedInVmBuild is not in 11.

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Commit messages:
 - Backport ab17be283559ba0477bc0dcbd11dbfccf155a57f

Changes: https://git.openjdk.org/jdk11u-dev/pull/2006/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk11u-dev&pr=2006&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8252530
  Stats: 9 lines in 4 files changed: 0 ins; 0 del; 9 mod
  Patch: https://git.openjdk.org/jdk11u-dev/pull/2006.diff
  Fetch: git fetch https://git.openjdk.org/jdk11u-dev.git pull/2006/head:pull/2006

PR: https://git.openjdk.org/jdk11u-dev/pull/2006