RFR: 8319761: Simplify fields of Array VarHandles

[ExE Boss]

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.

Note that the first change might need a **CSR** in case there’s user code out there which currently assumes it gets ownership over the identity of the result of calling `MethodHandles::arrayElementVarHandle(Class)` with a primitive array type.

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

PR Comment: https://git.openjdk.org/jdk/pull/15894#issuecomment-1735062158