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, 30 insertions, 0 deletions

diff --git a/tests/mir-opt/lower_array_len.array_len.NormalizeArrayLen.diff b/tests/mir-opt/lower_array_len.array_len.NormalizeArrayLen.diff
new file mode 100644
index 00000000000..3ed68f5f725
--- /dev/null
+++ b/tests/mir-opt/lower_array_len.array_len.NormalizeArrayLen.diff
@@ -0,0 +1,30 @@
+- // MIR for `array_len` before NormalizeArrayLen
++ // MIR for `array_len` after NormalizeArrayLen
+  
+  fn array_len(_1: &[u8; N]) -> usize {
+      debug arr => _1;                     // in scope 0 at $DIR/lower_array_len.rs:+0:34: +0:37
+      let mut _0: usize;                   // return place in scope 0 at $DIR/lower_array_len.rs:+0:52: +0:57
+      let mut _2: &[u8];                   // in scope 0 at $DIR/lower_array_len.rs:+1:5: +1:14
+      let mut _3: &[u8; N];                // in scope 0 at $DIR/lower_array_len.rs:+1:5: +1:14
++     let mut _4: &[u8; N];                // in scope 0 at $DIR/lower_array_len.rs:+1:5: +1:14
+  
+      bb0: {
+          StorageLive(_2);                 // scope 0 at $DIR/lower_array_len.rs:+1:5: +1:14
+          StorageLive(_3);                 // scope 0 at $DIR/lower_array_len.rs:+1:5: +1:14
+          _3 = &(*_1);                     // scope 0 at $DIR/lower_array_len.rs:+1:5: +1:14
++         StorageLive(_4);                 // scope 0 at $DIR/lower_array_len.rs:+1:5: +1:14
++         _4 = _3;                         // scope 0 at $DIR/lower_array_len.rs:+1:5: +1:14
+          _2 = move _3 as &[u8] (Pointer(Unsize)); // scope 0 at $DIR/lower_array_len.rs:+1:5: +1:14
+          StorageDead(_3);                 // scope 0 at $DIR/lower_array_len.rs:+1:7: +1:8
+-         _0 = Len((*_2));                 // scope 0 at $DIR/lower_array_len.rs:+1:5: +1:14
++         _0 = Len((*_4));                 // scope 0 at $DIR/lower_array_len.rs:+1:5: +1:14
++         StorageDead(_4);                 // scope 0 at $DIR/lower_array_len.rs:+1:5: +1:14
+          goto -> bb1;                     // scope 0 at $DIR/lower_array_len.rs:+1:5: +1:14
+      }
+  
+      bb1: {
+          StorageDead(_2);                 // scope 0 at $DIR/lower_array_len.rs:+1:13: +1:14
+          return;                          // scope 0 at $DIR/lower_array_len.rs:+2:2: +2:2
+      }
+  }
+