Rollup merge of #125477 - nnethercote:missed-rustfmt, r=compiler-errors

Run rustfmt on files that need it.

Somehow these files aren't properly formatted. By default `x fmt` and `x tidy` only check files that have changed against master, so if an ill-formatted file somehow slips in it can stay that way as long as it doesn't get modified(?)

I found these when I ran `x fmt` explicitly on every `.rs` file in the repo, while working on
https://github.com/rust-lang/compiler-team/issues/750.

src/tools/build_helper/src/lib.rs

@@ -1,5 +1,5 @@
 pub mod ci;
 pub mod git;
 pub mod metrics;
-pub mod util;
 pub mod stage0_parser;
+pub mod util;