Could non-build-related utilities be extracted to a separate package?

Hello!

I was wondering if it was possible to extract various analyzer-based utils. They aren't tied to `build`, but are useful for quite a lot of analyzer projects.

For example, I was thinking of:

- TypeChecker
- Revivable

I find myself commonly having to fork those utils out of source_gen when I'm working on an analyzer-based project that doesn't use code generation (such as linters)

I don't mind making such package myself. But I figured I'd ask first about an official stance on the topic.

Start by reviewing the existing TypeChecker and Revivable utilities in source_gen and how analyzer-based projects consume them. Determine the package boundaries and affected consumers before proposing an extraction; done means there is an agreed package design and migration path, rather than only an implementation of one utility.

Written by the indexing model from the issue text.