RFR: 8276337: Use override specifier in HeapDumper [v2]

[Leo Korinth]

On Fri, 5 Nov 2021 14:14:43 GMT, Leo Korinth <lkorinth at openjdk.org> wrote:

>> Use override specifier in HeapDumper. It is safer.
>
> Leo Korinth has updated the pull request incrementally with one additional commit since the last revision:
> 
>   restart failed github tests

Thanks Thomas and David!

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

PR: https://git.openjdk.java.net/jdk/pull/6274