Auto merge of #126607 - Oneirical:the-testern-world, r=jieyouxu

Rewrite `separate-link`, `separate-link-fail` and `allocator-shim-circular-deps` `run-make` tests to `ui` or `rmake`

Part of #121876 and the associated [Google Summer of Code project](https://blog.rust-lang.org/2024/05/01/gsoc-2024-selected-projects.html).

Author: bors