[crac] RFR: Collect CREngine child [v2]

[Dan Heidinga]

On Thu, 21 Apr 2022 09:10:00 GMT, Anton Kozlov <akozlov at openjdk.org> wrote:

>> When VM calls for CREngine it does not properly awaits termination of the engine. In case of `criuengine`, this could lead for a dangling process in the CRIU image [1]. This patch adds missing waitpid that eliminates the problem.
>> 
>> [1] https://github.com/openjdk/crac/blob/crac/src/java.base/unix/native/criuengine/criuengine.c#L68
>
> Anton Kozlov has updated the pull request with a new target base due to a merge or a rebase. The incremental webrev excludes the unrelated changes brought in by the merge/rebase. The pull request contains three additional commits since the last revision:
> 
>  - Check fork error
>  - Merge remote-tracking branch 'jdk/crac/crac' into crengine-child
>  - Collect CREngine child

Looks good to me

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Marked as reviewed by heidinga (Committer).

PR: https://git.openjdk.java.net/crac/pull/18