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/threads-sendsync/task-comm-11.rs b/tests/ui/threads-sendsync/task-comm-11.rs
new file mode 100644
index 00000000000..8541e143fb9
--- /dev/null
+++ b/tests/ui/threads-sendsync/task-comm-11.rs
@@ -0,0 +1,21 @@
+// run-pass
+#![allow(unused_must_use)]
+// pretty-expanded FIXME #23616
+// ignore-emscripten no threads support
+
+use std::sync::mpsc::{channel, Sender};
+use std::thread;
+
+fn start(tx: &Sender<Sender<isize>>) {
+    let (tx2, _rx) = channel();
+    tx.send(tx2).unwrap();
+}
+
+pub fn main() {
+    let (tx, rx) = channel();
+    let child = thread::spawn(move|| {
+        start(&tx)
+    });
+    let _tx = rx.recv().unwrap();
+    child.join();
+}