RFR: 8329368: Generational ZGC: Remove the unnecessary friend classes in ZAllocator

[Stefan Karlsson]

On Sun, 31 Mar 2024 16:12:51 GMT, Guoxiong Li <gli at openjdk.org> wrote:

> Hi all,
> 
> This trivial patch removes the unnecessary friend classes in `ZAllocator`. The tests `make test-tier1_gc` passed locally.
> 
> Thanks for taking the time to review.
> 
> Best Regards,
> -- Guoxiong

You also need to remove the blank line, so that the code follows the coding style ZGC uses.

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

Changes requested by stefank (Reviewer).

PR Review: https://git.openjdk.org/jdk/pull/18560#pullrequestreview-1972782570