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`

3 files changed, 5 insertions, 2 deletions

diff --git a/compiler/rustc_errors/src/markdown/parse.rs b/compiler/rustc_errors/src/markdown/parse.rs
index 69e7120e714..c44f136120a 100644
--- a/compiler/rustc_errors/src/markdown/parse.rs
+++ b/compiler/rustc_errors/src/markdown/parse.rs
@@ -1,6 +1,7 @@
-use crate::markdown::{MdStream, MdTree};
 use std::{iter, mem, str};
 
+use crate::markdown::{MdStream, MdTree};
+
 /// Short aliases that we can use in match patterns. If an end pattern is not
 /// included, this type may be variable
 const ANC_E: &[u8] = b">";
diff --git a/compiler/rustc_errors/src/markdown/tests/parse.rs b/compiler/rustc_errors/src/markdown/tests/parse.rs
index e2e3f354ff6..bfcb3de16fa 100644
--- a/compiler/rustc_errors/src/markdown/tests/parse.rs
+++ b/compiler/rustc_errors/src/markdown/tests/parse.rs
@@ -1,6 +1,7 @@
-use super::*;
 use ParseOpt as PO;
 
+use super::*;
+
 #[test]
 fn test_parse_simple() {
     let buf = "**abcd** rest";
diff --git a/compiler/rustc_errors/src/markdown/tests/term.rs b/compiler/rustc_errors/src/markdown/tests/term.rs
index bab47dcc175..e025870f055 100644
--- a/compiler/rustc_errors/src/markdown/tests/term.rs
+++ b/compiler/rustc_errors/src/markdown/tests/term.rs
@@ -1,5 +1,6 @@
 use std::io::BufWriter;
 use std::path::PathBuf;
+
 use termcolor::{BufferWriter, ColorChoice};
 
 use super::*;