"innermost", "outermost", "leftmost", and "rightmost" don't need hyphens

These are all standard dictionary words and don't require hyphenation.

compiler/rustc_parse/src/lexer/diagnostics.rs

@@ -85,7 +85,7 @@ pub(super) fn report_suspicious_mismatch_block(
         }
     }
 
-    // Find the inner-most span candidate for final report
+    // Find the innermost span candidate for final report
     let candidate_span =
         matched_spans.into_iter().rev().find(|&(_, same_ident)| !same_ident).map(|(span, _)| span);