Incorporate syntax highlighting into symbol outline view

Still need to figure out how to style the fuzzy match characters
now that there's syntax highlighting. Right now, they are
underlined in red.

crates/language/src/buffer.rs

@@ -1865,7 +1865,7 @@ impl BufferSnapshot {
                 let range = item_node.start_byte()..item_node.end_byte();
                 let mut text = String::new();
                 let mut name_ranges = Vec::new();
-                let mut text_runs = Vec::new();
+                let mut highlight_ranges = Vec::new();
 
                 for capture in mat.captures {
                     let node_is_name;
@@ -1903,7 +1903,11 @@ impl BufferSnapshot {
                         } else {
                             offset += chunk.text.len();
                         }
-                        text_runs.push((chunk.text.len(), chunk.highlight_style));
+                        if let Some(style) = chunk.highlight_style {
+                            let start = text.len();
+                            let end = start + chunk.text.len();
+                            highlight_ranges.push((start..end, style));
+                        }
                         text.push_str(chunk.text);
                         if offset >= range.end {
                             break;
@@ -1922,8 +1926,8 @@ impl BufferSnapshot {
                     depth: stack.len() - 1,
                     range: self.anchor_after(range.start)..self.anchor_before(range.end),
                     text,
-                    name_ranges: name_ranges.into_boxed_slice(),
-                    text_runs,
+                    name_ranges,
+                    highlight_ranges,
                 })
             })
             .collect::<Vec<_>>();