Remove usage of TypeSwitch.

src/EditorFeatures/CSharp/Highlighting/KeywordHighlighters/ReturnStatementHighlighter.cs

@@ -39,14 +39,13 @@ internal class ReturnStatementHighlighter : AbstractKeywordHighlighter<ReturnSta
         /// </summary>
         private void HighlightRelatedKeywords(SyntaxNode node, List<TextSpan> spans)
         {
-            node.TypeSwitch(
-                (ReturnStatementSyntax statement) =>
-                {
+            switch (node)
+            {
+                case ReturnStatementSyntax statement:
                     spans.Add(statement.ReturnKeyword.Span);
                     spans.Add(EmptySpan(statement.SemicolonToken.Span.End));
-                },
-                _ =>
-                {
+                    break;
+                default:
                     foreach (var child in node.ChildNodes())
                     {
                         // Only recurse if we have anything to do
@@ -55,7 +54,8 @@ private void HighlightRelatedKeywords(SyntaxNode node, List<TextSpan> spans)
                             HighlightRelatedKeywords(child, spans);
                         }
                     }
-                });
+                    break;
+            }
         }
     }
-}
+}
\ No newline at end of file