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`

10 files changed, 22 insertions, 17 deletions

diff --git a/compiler/rustc_data_structures/src/graph/dominators/mod.rs b/compiler/rustc_data_structures/src/graph/dominators/mod.rs
index d1d2de670b8..7cb013fdbd8 100644
--- a/compiler/rustc_data_structures/src/graph/dominators/mod.rs
+++ b/compiler/rustc_data_structures/src/graph/dominators/mod.rs
@@ -9,10 +9,11 @@
 //! Thomas Lengauer and Robert Endre Tarjan.
 //! <https://www.cs.princeton.edu/courses/archive/spr03/cs423/download/dominators.pdf>
 
-use super::ControlFlowGraph;
+use std::cmp::Ordering;
+
 use rustc_index::{Idx, IndexSlice, IndexVec};
 
-use std::cmp::Ordering;
+use super::ControlFlowGraph;
 
 #[cfg(test)]
 mod tests;
diff --git a/compiler/rustc_data_structures/src/graph/dominators/tests.rs b/compiler/rustc_data_structures/src/graph/dominators/tests.rs
index 39725ba4301..6c078ca7c6e 100644
--- a/compiler/rustc_data_structures/src/graph/dominators/tests.rs
+++ b/compiler/rustc_data_structures/src/graph/dominators/tests.rs
@@ -1,6 +1,5 @@
-use super::*;
-
 use super::super::tests::TestGraph;
+use super::*;
 
 #[test]
 fn diamond() {
diff --git a/compiler/rustc_data_structures/src/graph/implementation/mod.rs b/compiler/rustc_data_structures/src/graph/implementation/mod.rs
index 8cf4b4153db..43fdfe6ee0d 100644
--- a/compiler/rustc_data_structures/src/graph/implementation/mod.rs
+++ b/compiler/rustc_data_structures/src/graph/implementation/mod.rs
@@ -20,8 +20,9 @@
 //! the field `next_edge`). Each of those fields is an array that should
 //! be indexed by the direction (see the type `Direction`).
 
-use rustc_index::bit_set::BitSet;
 use std::fmt::Debug;
+
+use rustc_index::bit_set::BitSet;
 use tracing::debug;
 
 #[cfg(test)]
diff --git a/compiler/rustc_data_structures/src/graph/implementation/tests.rs b/compiler/rustc_data_structures/src/graph/implementation/tests.rs
index b4dbd65db94..32a6d9ec881 100644
--- a/compiler/rustc_data_structures/src/graph/implementation/tests.rs
+++ b/compiler/rustc_data_structures/src/graph/implementation/tests.rs
@@ -1,6 +1,7 @@
-use crate::graph::implementation::*;
 use tracing::debug;
 
+use crate::graph::implementation::*;
+
 type TestGraph = Graph<&'static str, &'static str>;
 
 fn create_graph() -> TestGraph {
diff --git a/compiler/rustc_data_structures/src/graph/iterate/mod.rs b/compiler/rustc_data_structures/src/graph/iterate/mod.rs
index 6fca57d32f7..cbc6664d853 100644
--- a/compiler/rustc_data_structures/src/graph/iterate/mod.rs
+++ b/compiler/rustc_data_structures/src/graph/iterate/mod.rs
@@ -1,7 +1,9 @@
-use super::{DirectedGraph, StartNode, Successors};
+use std::ops::ControlFlow;
+
 use rustc_index::bit_set::BitSet;
 use rustc_index::{IndexSlice, IndexVec};
-use std::ops::ControlFlow;
+
+use super::{DirectedGraph, StartNode, Successors};
 
 #[cfg(test)]
 mod tests;
diff --git a/compiler/rustc_data_structures/src/graph/iterate/tests.rs b/compiler/rustc_data_structures/src/graph/iterate/tests.rs
index c498c289337..eb7d0bd14b6 100644
--- a/compiler/rustc_data_structures/src/graph/iterate/tests.rs
+++ b/compiler/rustc_data_structures/src/graph/iterate/tests.rs
@@ -1,5 +1,4 @@
 use super::super::tests::TestGraph;
-
 use super::*;
 
 #[test]
diff --git a/compiler/rustc_data_structures/src/graph/scc/mod.rs b/compiler/rustc_data_structures/src/graph/scc/mod.rs
index 8b96b36a851..96fc8ae3887 100644
--- a/compiler/rustc_data_structures/src/graph/scc/mod.rs
+++ b/compiler/rustc_data_structures/src/graph/scc/mod.rs
@@ -8,14 +8,16 @@
 //! Typical examples would include: minimum element in SCC, maximum element
 //! reachable from it, etc.
 
-use crate::fx::FxHashSet;
-use crate::graph::vec_graph::VecGraph;
-use crate::graph::{DirectedGraph, NumEdges, Successors};
-use rustc_index::{Idx, IndexSlice, IndexVec};
 use std::fmt::Debug;
 use std::ops::Range;
+
+use rustc_index::{Idx, IndexSlice, IndexVec};
 use tracing::{debug, instrument};
 
+use crate::fx::FxHashSet;
+use crate::graph::vec_graph::VecGraph;
+use crate::graph::{DirectedGraph, NumEdges, Successors};
+
 #[cfg(test)]
 mod tests;
 
diff --git a/compiler/rustc_data_structures/src/graph/tests.rs b/compiler/rustc_data_structures/src/graph/tests.rs
index 85c2703cc25..b69b9dbc4a8 100644
--- a/compiler/rustc_data_structures/src/graph/tests.rs
+++ b/compiler/rustc_data_structures/src/graph/tests.rs
@@ -1,7 +1,7 @@
-use crate::fx::FxHashMap;
 use std::cmp::max;
 
 use super::*;
+use crate::fx::FxHashMap;
 
 pub struct TestGraph {
     num_nodes: usize,
diff --git a/compiler/rustc_data_structures/src/graph/vec_graph/mod.rs b/compiler/rustc_data_structures/src/graph/vec_graph/mod.rs
index 120244c8918..96784c2540a 100644
--- a/compiler/rustc_data_structures/src/graph/vec_graph/mod.rs
+++ b/compiler/rustc_data_structures/src/graph/vec_graph/mod.rs
@@ -1,6 +1,7 @@
-use crate::graph::{DirectedGraph, NumEdges, Predecessors, Successors};
 use rustc_index::{Idx, IndexVec};
 
+use crate::graph::{DirectedGraph, NumEdges, Predecessors, Successors};
+
 #[cfg(test)]
 mod tests;
 
diff --git a/compiler/rustc_data_structures/src/graph/vec_graph/tests.rs b/compiler/rustc_data_structures/src/graph/vec_graph/tests.rs
index a077d9d0813..78caf75f5b4 100644
--- a/compiler/rustc_data_structures/src/graph/vec_graph/tests.rs
+++ b/compiler/rustc_data_structures/src/graph/vec_graph/tests.rs
@@ -1,6 +1,5 @@
-use crate::graph;
-
 use super::*;
+use crate::graph;
 
 fn create_graph() -> VecGraph<usize> {
     // Create a simple graph