RFR: 8319761: Simplify fields of Array VarHandles

[Per Minborg]

On Sun, 24 Sep 2023 13:17:05 GMT, Chen Liang <liach at openjdk.org> wrote:

> 1. Primitive array VHs are now singletons and no longer need to record their array base and offset in their object themselves.
> 2. Moved Unsafe offset calculation to a utility method, like `index` in VarHandleByteArrayView.

Sharing code might sometimes have performance issues because the shared code is used differently from different call sites. See https://bugs.openjdk.org/browse/JDK-8015417.   Is this something we should check here?

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

PR Comment: https://git.openjdk.org/jdk/pull/15894#issuecomment-1803312528