RFR: 8351319: AOT cache support for custom class loaders broken since JDK-8348426

[Ioi Lam]

Since [JDK-8348426](https://bugs.openjdk.org/browse/JDK-8348426) (Generate binary file for -XX:AOTMode=record -XX:AOTConfiguration=file), the AOT cache no longer contains classes intended for custom class loaders (these are called "unregistered classes" in CDS terminology).

The fix is simple -- we already remember the set of unregistered classes in the AOT configuration file. We just need to add them into the final AOT cache (see changes in finalImageRecipes.cpp).

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Commit messages:
 - 8351319: AOT cache support for custom class loaders broken since JDK-8348426

Changes: https://git.openjdk.org/jdk/pull/23926/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=23926&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8351319
  Stats: 122 lines in 10 files changed: 98 ins; 1 del; 23 mod
  Patch: https://git.openjdk.org/jdk/pull/23926.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/23926/head:pull/23926

PR: https://git.openjdk.org/jdk/pull/23926