Fix soundness problem with Array.chop

[jasoncarr0]

While the memory of the two array pieces was disjoint, a non-sendable element type could allow aliases between the two array portions that would violate isolation.

Fixes #3652

[ponylang-main]

Hi @jasoncarr0,

The changelog - fixed label was added to this pull request; all PRs with a changelog label need to have release notes included as part of the PR. If you haven't added release notes already, please do.

Release notes are added by creating a uniquely named file in the .release-notes directory. We suggest you call the file 3657.md to match the number of this pull request.

The basic format of the release notes (using markdown) should be:

## Title

End user description of changes, why it's important,
problems it solves etc.

If a breaking change, make sure to include 1 or more
examples what code would look like prior to this change
and how to update it to work after this change.

Thanks.

[SeanTAllen]

I think this could use some elaboration; the example you gave in the issue would be good here as not everyone is going to understand what this means.

[SeanTAllen]

Can you change this to be Fix soundness problem with Array.chop

It's a much clearer end user "what was the issue" headline.

[jasoncarr0]

Sure thing, changed

[SeanTAllen]

Thanks @jasoncarr0.