RFR: 8349009: JVM fails to start when AOTClassLinking is used with unverifiable old classes

[Ioi Lam]

During the testing of [JDK-8348752](https://bugs.openjdk.org/browse/JDK-8348752), we notice test failures caused by unverifiable old classes (i.e., classes with bad instructions and major version < 50).

The fix is simple. Simply exclude unlinked classes from the AOTCache when `-XX:+AOTClassLinking` is enabled.

Verified with JCK.

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Commit messages:
 - 8349009: JVM fails to start when AOTClassLinking is used with unverifiable old classes

Changes: https://git.openjdk.org/jdk/pull/23361/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=23361&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8349009
  Stats: 104 lines in 4 files changed: 101 ins; 0 del; 3 mod
  Patch: https://git.openjdk.org/jdk/pull/23361.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/23361/head:pull/23361

PR: https://git.openjdk.org/jdk/pull/23361