RFR: 8306474: Move InstanceKlass read-only flags

[Coleen Phillimore]

Moved three read-only InstanceKlass flags out of AccessFlags to InstanceKlassFlags, and removed unused and unneeded SA code.
Tested with tier1-4.

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Commit messages:
 - 8306474: Move InstanceKlass read-only flags

Changes: https://git.openjdk.org/jdk/pull/13545/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=13545&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8306474
  Stats: 44 lines in 10 files changed: 11 ins; 26 del; 7 mod
  Patch: https://git.openjdk.org/jdk/pull/13545.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/13545/head:pull/13545

PR: https://git.openjdk.org/jdk/pull/13545