Improve inferred pure @nogc notrhow errors

[dkorpel]

Expand #13957 to @nogc and pure errors

https://issues.dlang.org/show_bug.cgi?id=17374

Inspired by Blog post on figuring out attribute inference failure

[dlang-bot]

Thanks for your pull request and interest in making D better, @dkorpel! We are looking forward to reviewing it, and you should be hearing from a maintainer soon.
Please verify that your PR follows this checklist:

• My PR is fully covered with tests (you can see the coverage diff by visiting the details link of the codecov check)
• My PR is as minimal as possible (smaller, focused PRs are easier to review than big ones)
• I have provided a detailed rationale explaining my changes
• New or modified functions have Ddoc comments (with Params: and Returns:)

Please see CONTRIBUTING.md for more information.

---

If you have addressed all reviews or aren't sure how to proceed, don't hesitate to ping us with a simple comment.

Bugzilla references

Your PR doesn't reference any Bugzilla issue.

If your PR contains non-trivial changes, please reference a Bugzilla issue or create a manual changelog.

Testing this PR locally

If you don't have a local development environment setup, you can use Digger to test this PR:

dub run digger -- build "master + dmd#14911"

[schveiguy]

Awesome! Is nothrow hard to do at the same time?

[dkorpel]

Awesome! Is nothrow hard to do at the same time?

It's a bit harder because it's not checked directly in expression semantic like the others, considering it needs to account for catch blocks, but it should be doable with a little refactoring.