Merge pull request #4409 from rust-lang/rustup-2025-06-20

Automatic Rustup

Author: RalfJung

src/tests/ui.md

@@ -13,6 +13,11 @@ used for many other purposes. For example, tests can also be configured to [run
 the resulting program](#controlling-passfail-expectations) to verify its
 behavior.
 
+For a survey of each subdirectory's purpose under `tests/ui`, consult the
+[SUMMARY.md](https://github.com/rust-lang/rust/tree/master/tests/ui/SUMMARY.md).
+This is useful if you write a new test, and are looking for a category to
+place it in.
+
 If you need to work with `#![no_std]` cross-compiling tests, consult the
 [`minicore` test auxiliary](./minicore.md) chapter.