Fix recursion limits with next solver

[nazar-pc]

Connections

#9608, #9609

Description

This is a much better alternative to #9609 that solves the same underlying issue. The root cause is that next solver has a really hard time figuring out auto traits and ultimately fails with default recursion limit.

I later discovered that this is infectious, meaning not only wgpu needs to raise limits, but any crate that uses a lot of its types. The solution is to help solver a little bit and implement the traits manually. The code is more or less a macro expansion from https://crates.io/crates/non_structural_derive applied to the core type that is used basically everywhere.

This small change removes the need to increase recursion limits both here and for downstream users and I believe should help with compilation time as well.

Testing

Checked whether workspace compiles with cargo clippy.

Checklist

• I self-reviewed and fully understand this PR.
• WebGPU implementations built with wgpu may be affected behaviorally.
• Validation and feature gates are in place to confine behavioral changes.
• Tests demonstrate the validation and altered logic works.
• CHANGELOG.md entries for the user-facing effects of this change are present.
• The PR is minimal, and doesn't make sense to land as multiple PRs.
• Commits are logically scoped and individually reviewable.
• The PR description has enough context to understand the motivation and solution implemented.

[nazar-pc]

Changelog fails because I replaced one non-break space character with a normal whitespace. It likely was a typo originally and my IDE warns about all kinds of invisible or strange characters like that. I can roll it back if you'd really want me to.

[jimblandy]

Thank you very much!

[jimblandy]

Actually, please make the change Andy suggested.

[kpreid]

I resolved the changelog conflict, and while I was there, broke out the whitespace fix to a separate commit and rewrote the changelog message to clarify its user-facing implications.