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, 0 insertions, 9 deletions

diff --git a/src/test/ui/parser/variadic-ffi-nested-syntactic-fail.rs b/src/test/ui/parser/variadic-ffi-nested-syntactic-fail.rs
deleted file mode 100644
index 9eeee195e56..00000000000
--- a/src/test/ui/parser/variadic-ffi-nested-syntactic-fail.rs
+++ /dev/null
@@ -1,9 +0,0 @@
-fn f1<'a>(x: u8, y: &'a ...) {}
-//~^ ERROR C-variadic type `...` may not be nested inside another type
-
-fn f2<'a>(x: u8, y: Vec<&'a ...>) {}
-//~^ ERROR C-variadic type `...` may not be nested inside another type
-
-fn main() {
-    let _recovery_witness: () = 0; //~ ERROR mismatched types
-}