Packed bundle assignment bug

[dokleina]

Updated PackedBundle's packed method to avoid Assignment Overlap errors when the Bundle contains only a single field.

Context, Motivation & Description

As demonstrated in #1441, a PackedBundle with a single field can cause an ASSIGNMENT OVERLAP error. This is likely because assignment completely re-assigns an internal Bits buffer object, whereas in the case of multiple fields, no one single field overwrites the entire buffer. Adding allowOverride to the buffer clears up the issue.

Impact on code generation

None anticipated or expected.

Checklist

• [x] Unit tests were added
• [x] API changes are or will be documented:
  • using Scaladoc comments: /** */?
  • on RTD?
  • thanks to a new tracking issue on RTD?

[dokleina]

I don't understand why lib-test failed, it almost looks like it might have timed out or something. Nothing I added in this PR should have broken it.

[Dolu1990]

It seems that the CI was canceled by some ways i rerun it, your changes seems good to me aswell.

[Dolu1990]

Thanks ^^