Redo [JDK-8301378](https://bugs.openjdk.org/browse/JDK-8301378), this time also fixing the serviceability code.
------------- Commit messages: - Redo removal of virtual methods in CodeHeap Changes: https://git.openjdk.org/jdk/pull/12345/files Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=12345&range=00 Issue: https://bugs.openjdk.org/browse/JDK-8301447 Stats: 10 lines in 2 files changed: 0 ins; 5 del; 5 mod Patch: https://git.openjdk.org/jdk/pull/12345.diff Fetch: git fetch https://git.openjdk.org/jdk pull/12345/head:pull/12345 PR: https://git.openjdk.org/jdk/pull/12345
