Fade out unnecessary code

Co-Authored-By: Nathan Sobo <nathan@zed.dev>

crates/editor/src/display_map/block_map.rs

@@ -819,7 +819,8 @@ impl<'a> Iterator for BlockChunks<'a> {
                 text: unsafe { std::str::from_utf8_unchecked(&NEWLINES[..line_count as usize]) },
                 syntax_highlight_id: None,
                 highlight_style: None,
-                diagnostic: None,
+                diagnostic_severity: None,
+                is_unnecessary: false,
             });
         }
 

crates/editor/src/display_map/fold_map.rs

@@ -1078,7 +1078,8 @@ impl<'a> Iterator for FoldChunks<'a> {
                 text: output_text,
                 syntax_highlight_id: None,
                 highlight_style: None,
-                diagnostic: None,
+                diagnostic_severity: None,
+                is_unnecessary: false,
             });
         }