Escape Zero-size types in playback

[YoshikiTakashima]

Description of changes:

This PR adds an escape in the concrete playback for zero-size types
where the previous implementation was crashing for.

Resolved issues:

Resolves #2453

Testing:

• How is this change tested? c7f9044

• Is this a refactor change? no

Checklist

• Each commit message has a non-empty body, explaining why the change was made
• Methods or procedures are documented
• Regression or unit tests are included, or existing tests cover the modified code
• My PR is restricted to a single feature or bugfix

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 and MIT licenses.

[celinval]

Thanks

[YoshikiTakashima]

That's an interesting bug: 2 harnesses came out with exactly the same names... I'll investigate.

[YoshikiTakashima]

OK. This is a bug that is separate. It's the interaction between ZST and multi-harness. Tracking: #2509. I will merge this one with a reduced test case, and then fix that issue.