Understand frame traces

[roberth]

This issue is somewhat of a personal note while I work on traces every now and then. Gathering knowledge here helps me and possibly others until the "problem" is solved.

Is your feature request related to a problem? Please describe.

Frame traces are a mystery to me, and presumably others.

Their use has expanded around the time we unreversed the stack trace printing order. I suspect something about these changes might interact wrong.

I've had to remove the stop after frame logic to get some things to print in

• Stack overflow: stack trace and nix debugger support #8879

Describe the solution you'd like

• Make frame traces more explicit in the code. greppable. Refactor it to use a recognizable identifier instead of a positional bool.
• Add tests to cover the apparent intent of each frame trace and make changes observable.
• Make changes and see whether the traces improve. I expect they will.

Describe alternatives you've considered

N/A.

Additional context

Priorities

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