Rollup merge of #133567 - bjorn3:various_cleanups, r=cjgillot

A bunch of cleanups

These are all extracted from a branch I have to get rid of driver queries. Most of the commits are not directly necessary for this, but were found in the process of implementing the removal of driver queries.

Previous PR: rust-lang/rust#132410

Author: matthiaskrgr

src/bin/miri.rs

@@ -289,7 +289,8 @@ fn run_compiler(
     let exit_code = rustc_driver::catch_with_exit_code(move || {
         rustc_driver::RunCompiler::new(&args, callbacks)
             .set_using_internal_features(using_internal_features)
-            .run()
+            .run();
+        Ok(())
     });
     std::process::exit(exit_code)
 }