RFR: 8368199: Add @AOTSafeClassInitializer to jdk.internal.access.SharedSecrets

[Ioi Lam]

By annotating `SharedSecrets` as `@AOTSafeClassInitializer`, we can avoid using the `@AOTRuntimeSetup` annotations in a few JDK core classes. This simplifies the implementation. It also brings us closer to the goal of making the AOT cache as a true snapshot of the JVM state that just needs to be resumed in the production run.

-------------

Commit messages:
 - 8368199: Add @AOTSafeClassInitializer to jdk.internal.access.SharedSecrets

Changes: https://git.openjdk.org/jdk/pull/27880/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=27880&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8368199
  Stats: 38 lines in 7 files changed: 5 ins; 30 del; 3 mod
  Patch: https://git.openjdk.org/jdk/pull/27880.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/27880/head:pull/27880

PR: https://git.openjdk.org/jdk/pull/27880