RFR: 8251397: Add release fence to ClassValueMap constructor

[Severin Gehwolf]

On Mon, 14 Sep 2020 08:03:51 GMT, Galder Zamarreño <github.com+50187+galderz at openjdk.org> wrote:

>> Please ensure the PR title and the bug synopsis match before this in integrated!
>> 
>> Please DO NOT force-push updates as you lose the history of commits and anyone following this cannot see what changes
>> were actually made at each step! You do not need to worry about intermediate commits as they will only appear in your
>> branch and in the PR. The actual committed changeset will be a single flattened version of your changes.
>
> Are you expecting anything else from me? @jerboaa already proposed as sponsor above.

@galderz The PR has this synopsis `8251397: Add release fence to ClassValueMap constructor`. The bug has this `8251397:
NPE on ClassValue.ClassValueMap.cacheArray`. @dholmes-ora asked to make them matching. Let's fix that first.

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

PR: https://git.openjdk.java.net/jdk/pull/94