Split run-make test suite into slower-building test suite with suitably-staged cargo and faster-building test suite without cargo

[jieyouxu]

Proposal

Split run-make test suite into two test suites to allow contributors to not have to build cargo if the run-make test doesn't need it:

1. A "slow" test suite that requires building a suitably-staged cargo, and thus allowing cargo() usages.
2. A "fast" test suite that does not build cargo.

rustc-dev-guide and test suite README doc updates will be provided alongside the implementation PR(s).

See also rust-lang/rust#134109 and rust-lang/rust#135573.

Unresolved questions

How to distinguish between "minimal" and "full" configuration?

After discussion, I decided to make this distinction "build cargo or not".

Naming

I decided to constrain this MCP to focus on doing the functional test suite splitting. Naming is orthogonal.

I will go with {run-make,run-make-cargo} for now.

Mentors or Reviewers

The implementation will be bootstrap reviews primarily, MCP is for figuring out a naming scheme / vibe check / for awareness, really.

cc @WaffleLapkin who didn't really like that the run-make test suite is still called run-make when there's no make involved (understandably :D).

cc @petrochenkov, @bjorn3 and @RalfJung who asked about if it's possible/planned to not have to fully build cargo (which takes a good while).

Process

The main points of the Major Change Process are as follows:

• File an issue describing the proposal.
• A compiler team member or contributor who is knowledgeable in the area can second by writing @rustbot second.
  • Finding a "second" suffices for internal changes. If however, you are proposing a new public-facing feature, such as a -C flag, then full team check-off is required.
  • Compiler team members can initiate a check-off via @rfcbot fcp merge on either the MCP or the PR.
• Once an MCP is seconded, the Final Comment Period begins. If no objections are raised after 10 days, the MCP is considered approved.

You can read more about Major Change Proposals on forge.

[rustbot]

Important

This issue is not meant to be used for technical discussion. There is a Zulip stream for that.
Use this issue to leave procedural comments, such as volunteering to review, indicating that you second the proposal (or third, etc), or raising a concern that you would like to be addressed.

Concerns or objections can formally be registered here by adding a comment.

@rfcbot concern reason-for-concern
<description of the concern>

Concerns can be lifted with:

@rfcbot resolve reason-for-concern

See documentation at https://forge.rust-lang.org

cc @rust-lang/compiler

[Kobzol]

@rustbot second