Reformat use declarations.

The previous commit updated `rustfmt.toml` appropriately. This commit is
the outcome of running `x fmt --all` with the new formatting options.

library/proc_macro/src/lib.rs

@@ -45,16 +45,17 @@ pub mod bridge;
 mod diagnostic;
 mod escape;
 
-#[unstable(feature = "proc_macro_diagnostic", issue = "54140")]
-pub use diagnostic::{Diagnostic, Level, MultiSpan};
-
-use crate::escape::{escape_bytes, EscapeOptions};
 use std::ffi::CStr;
 use std::ops::{Range, RangeBounds};
 use std::path::PathBuf;
 use std::str::FromStr;
 use std::{error, fmt};
 
+#[unstable(feature = "proc_macro_diagnostic", issue = "54140")]
+pub use diagnostic::{Diagnostic, Level, MultiSpan};
+
+use crate::escape::{escape_bytes, EscapeOptions};
+
 /// Determines whether proc_macro has been made accessible to the currently
 /// running program.
 ///