Simplify the boilerplate code in jvm.cpp that calls `JvmtiThreadState::class_to_verify_considering_redefinition()`, and reduce the number of `InstanceKlass::cast()` calls.
I also changed a few fields/arguments from `Klass*` to `InstanceKlass*` as these are used exclusively with `InstanceKlass*`. ------------- Commit messages: - 8367719: Refactor JNI code that uses class_to_verify_considering_redefinition() Changes: https://git.openjdk.org/jdk/pull/27303/files Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=27303&range=00 Issue: https://bugs.openjdk.org/browse/JDK-8367719 Stats: 128 lines in 3 files changed: 26 ins; 33 del; 69 mod Patch: https://git.openjdk.org/jdk/pull/27303.diff Fetch: git fetch https://git.openjdk.org/jdk.git pull/27303/head:pull/27303 PR: https://git.openjdk.org/jdk/pull/27303
