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`

2 files changed, 5 insertions, 6 deletions

diff --git a/compiler/rustc_codegen_cranelift/example/alloc_system.rs b/compiler/rustc_codegen_cranelift/example/alloc_system.rs
index 441f3cd2987..2884c9c32ae 100644
--- a/compiler/rustc_codegen_cranelift/example/alloc_system.rs
+++ b/compiler/rustc_codegen_cranelift/example/alloc_system.rs
@@ -8,8 +8,7 @@ pub struct System;
 #[cfg(any(windows, unix, target_os = "redox"))]
 mod realloc_fallback {
     use core::alloc::{GlobalAlloc, Layout};
-    use core::cmp;
-    use core::ptr;
+    use core::{cmp, ptr};
     impl super::System {
         pub(crate) unsafe fn realloc_fallback(
             &self,
@@ -34,6 +33,7 @@ mod platform {
     use core::alloc::{GlobalAlloc, Layout};
     use core::ffi::c_void;
     use core::ptr;
+
     use System;
     extern "C" {
         fn posix_memalign(memptr: *mut *mut c_void, align: usize, size: usize) -> i32;
@@ -71,6 +71,7 @@ mod platform {
 #[allow(nonstandard_style)]
 mod platform {
     use core::alloc::{GlobalAlloc, Layout};
+
     use System;
     type LPVOID = *mut u8;
     type HANDLE = LPVOID;
diff --git a/compiler/rustc_codegen_cranelift/example/arbitrary_self_types_pointers_and_wrappers.rs b/compiler/rustc_codegen_cranelift/example/arbitrary_self_types_pointers_and_wrappers.rs
index f7edfa960a2..5479b0c617b 100644
--- a/compiler/rustc_codegen_cranelift/example/arbitrary_self_types_pointers_and_wrappers.rs
+++ b/compiler/rustc_codegen_cranelift/example/arbitrary_self_types_pointers_and_wrappers.rs
@@ -2,10 +2,8 @@
 
 #![feature(arbitrary_self_types, unsize, coerce_unsized, dispatch_from_dyn)]
 
-use std::{
-    marker::Unsize,
-    ops::{CoerceUnsized, Deref, DispatchFromDyn},
-};
+use std::marker::Unsize;
+use std::ops::{CoerceUnsized, Deref, DispatchFromDyn};
 
 struct Ptr<T: ?Sized>(Box<T>);