inline format!() args up to and including rustc_middle

compiler/rustc_middle/src/util/bug.rs

@@ -29,7 +29,7 @@ fn opt_span_bug_fmt<S: Into<MultiSpan>>(
     location: &Location<'_>,
 ) -> ! {
     tls::with_opt(move |tcx| {
-        let msg = format!("{}: {}", location, args);
+        let msg = format!("{location}: {args}");
         match (tcx, span) {
             (Some(tcx), Some(span)) => tcx.sess.diagnostic().span_bug(span, msg),
             (Some(tcx), None) => tcx.sess.diagnostic().bug(msg),

compiler/rustc_middle/src/util/common.rs

@@ -17,7 +17,7 @@ pub fn to_readable_str(mut val: usize) -> String {
             groups.push(group.to_string());
             break;
         } else {
-            groups.push(format!("{:03}", group));
+            groups.push(format!("{group:03}"));
         }
     }