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.

compiler/rustc_codegen_gcc/build_system/src/prepare.rs

@@ -1,12 +1,12 @@
+use std::fs;
+use std::path::{Path, PathBuf};
+
 use crate::rustc_info::get_rustc_path;
 use crate::utils::{
     cargo_install, create_dir, get_sysroot_dir, git_clone_root_dir, remove_file, run_command,
     run_command_with_output, walk_dir,
 };
 
-use std::fs;
-use std::path::{Path, PathBuf};
-
 fn prepare_libcore(
     sysroot_path: &Path,
     libgccjit12_patches: bool,