Fix invalid bounding box

(cherry picked from commit d558f6a)

Author: estebank

src/librustc_errors/lib.rs

@@ -181,7 +181,7 @@ impl CodeSuggestion {
 
             // Find the bounding span.
             let lo = substitution.parts.iter().map(|part| part.span.lo()).min().unwrap();
-            let hi = substitution.parts.iter().map(|part| part.span.hi()).min().unwrap();
+            let hi = substitution.parts.iter().map(|part| part.span.hi()).max().unwrap();
             let bounding_span = Span::with_root_ctxt(lo, hi);
             let lines = cm.span_to_lines(bounding_span).unwrap();
             assert!(!lines.lines.is_empty());