RFR: 8313905: Checked_cast assert in CDS compare_by_loader

[Coleen Phillimore]

Fix a checked_cast<> assert caused by changes to CDS code, but not using address calculations for comparison operators for class loaders or InstanceKlass pointers.
Tested with tier1-4 on linux-x64-debug and windows-x64-debug.

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Commit messages:
 - 8313905: Checked_cast assert in CDS compare_by_loader

Changes: https://git.openjdk.org/jdk/pull/15208/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=15208&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8313905
  Stats: 7 lines in 2 files changed: 5 ins; 0 del; 2 mod
  Patch: https://git.openjdk.org/jdk/pull/15208.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/15208/head:pull/15208

PR: https://git.openjdk.org/jdk/pull/15208