misc: remove stale comment

src/source_impls.rs

@@ -72,15 +72,6 @@ fn context_info<'a>(
         offset += 1;
     }
 
-    // These lines are commented as a hat-tip towards better failures. For the
-    // case of error reporting _specifically_, exposing a bug in your own
-    // error span calculation code by crashing with an opaque fmt::Error is
-    // not ideal. Instead, we go ahead and return what we've collected so far
-    // in out-of-range cases and just let it render without or with a missing
-    // label.
-    //
-    // Old code is left here in case we change our minds and we want to bring back more strict calculation.
-
     if offset >= (span.offset() + span.len()).saturating_sub(1) {
         let starting_offset = before_lines_starts.get(0).copied().unwrap_or_else(|| {
             if line_count > 0 {