RFR: 8329494: Serial: Merge GenMarkSweep into MarkSweep

[Magnus Ihse Bursie]

On Wed, 3 Apr 2024 03:10:26 GMT, Guoxiong Li <gli at openjdk.org> wrote:

> Hi all,
> 
> This patch merges the class `GenMarkSweep` into `MarkSweep`. Just simply move. It may be better to merge the class `DeadSpacer` and `Compacter` into `MarkSweep` and then rename `MarkSweep`. The `MarkSweep` will be renamed at [JDK-8329521](https://bugs.openjdk.org/browse/JDK-8329521). And the `DeadSpacer` and `Compacter` may be refactored at [JDK-8305896](https://bugs.openjdk.org/browse/JDK-8305896) and [JDK-8305898](https://bugs.openjdk.org/browse/JDK-8305898), so I don't refactor them now.
> 
> The tests `make test-tier1_gc` passed locally. Thanks for taking the time to review.
> 
> Best Regards,
> -- Guoxiong

Build changes are trivially fine.

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Marked as reviewed by ihse (Reviewer).

PR Review: https://git.openjdk.org/jdk/pull/18589#pullrequestreview-1976202642