Auto merge of #106458 - albertlarsan68:move-tests, r=jyn514

Move src/test to the root

See MCP at rust-lang/compiler-team#573

There may be more changes needed.

The first commit is just the move of the files:
You can check that the first commit did not do anything else than renames by running
```
git diff --diff-filter=r -M100% <rust-lang remote>/master <first commit hash>
```
The output should be empty, because the filter excludes renames, and the match threshold for qualifying a rename is 100%.

The second one is mostly a "find and replace" of `src/test` to `tests` and whatever is needed to make CI pass.

What is left to do:
---

- [x] Move directory
- [ ] Change references to `src/test`
    - [x] Change references in-tree
    - [ ] Change references in submodules / out-of-tree docs
- [x] Make CI pass:
    - [x] Fix tidy
    - [x] Fix tests
    - [x] Bless tests if needed (shouldn't normally)
- [ ] Merge it !

1 files changed, 21 insertions, 0 deletions

diff --git a/tests/ui/structs-enums/struct-rec/mutual-struct-recursion.rs b/tests/ui/structs-enums/struct-rec/mutual-struct-recursion.rs
new file mode 100644
index 00000000000..3bfce8b4f96
--- /dev/null
+++ b/tests/ui/structs-enums/struct-rec/mutual-struct-recursion.rs
@@ -0,0 +1,21 @@
+struct A<T> {
+//~^ ERROR recursive types `A` and `B` have infinite size
+    x: T,
+    y: B<T>,
+}
+
+struct B<T> {
+    z: A<T>
+}
+
+struct C<T> {
+//~^ ERROR recursive types `C` and `D` have infinite size
+    x: T,
+    y: Option<Option<D<T>>>,
+}
+
+struct D<T> {
+    z: Option<Option<C<T>>>,
+}
+
+fn main() {}