Auto merge of #125443 - nnethercote:rustfmt-use-decls, r=lcnr,cuviper,GuillaumeGomez

rustfmt `use` declarations

This PR implements https://github.com/rust-lang/compiler-team/issues/750, which changes how `use` declarations are formatted by adding these options to `rustfmt.toml`:
```
group_imports = "StdExternalCrate"
imports_granularity = "Module"
```

r? `@ghost`

1 files changed, 2 insertions, 1 deletions

diff --git a/library/alloc/src/raw_vec/tests.rs b/library/alloc/src/raw_vec/tests.rs
index 4194be53061..48c6e5f46f8 100644
--- a/library/alloc/src/raw_vec/tests.rs
+++ b/library/alloc/src/raw_vec/tests.rs
@@ -1,7 +1,8 @@
-use super::*;
 use core::mem::size_of;
 use std::cell::Cell;
 
+use super::*;
+
 #[test]
 fn allocator_param() {
     use crate::alloc::AllocError;