[clangd] Fix uninit member

Author: sam-mccall

clang-tools-extra/clangd/Protocol.h

@@ -981,7 +981,7 @@ struct DocumentSymbol {
   SymbolKind kind;
 
   /// Indicates if this symbol is deprecated.
-  bool deprecated;
+  bool deprecated = false;
 
   /// The range enclosing this symbol not including leading/trailing whitespace
   /// but everything else like comments. This information is typically used to