Removed redundant APIs in `JavaLangReflectAccess` and added general warning against using `SharedSecrets`.
------------- Commit messages: - 8336934: Clean up JavaLangReflectAccess Changes: https://git.openjdk.org/jdk/pull/20290/files Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=20290&range=00 Issue: https://bugs.openjdk.org/browse/JDK-8336934 Stats: 185 lines in 6 files changed: 19 ins; 147 del; 19 mod Patch: https://git.openjdk.org/jdk/pull/20290.diff Fetch: git fetch https://git.openjdk.org/jdk.git pull/20290/head:pull/20290 PR: https://git.openjdk.org/jdk/pull/20290
