[clangd] Enable designator inlay hints by default.

clang-tools-extra/clangd/Config.h

 #ifndef LLVM_CLANG_TOOLS_EXTRA_CLANGD_CONFIG_H
 #define LLVM_CLANG_TOOLS_EXTRA_CLANGD_CONFIG_H
 
 #include "support/Context.h"
 #include "llvm/ADT/FunctionExtras.h"
 #include "llvm/ADT/Optional.h"
 #include "llvm/ADT/StringMap.h"
 #include "llvm/ADT/StringSet.h"
-#include "llvm/Support/Regex.h"
 #include <functional>
 #include <string>
 #include <vector>
 
 namespace clang {
 namespace clangd {
 
 /// Settings that express user/project preferences and control clangd behavior.
struct Config {
 
   struct {
     /// If false, inlay hints are completely disabled.
     bool Enabled = true;
 
     // Whether specific categories of hints are enabled.
     bool Parameters = true;
     bool DeducedTypes = true;
-    bool Designators = false;
+    bool Designators = true;
   } InlayHints;
 };
 
 } // namespace clangd
 } // namespace clang
 
 namespace llvm {
 template <> struct DenseMapInfo<clang::clangd::Config::ExternalIndexSpec> {