[clangd][NFC] Don't store symbolmap on the heap

[njames93]

Summary

Storing this on the heap doesn't make any sense. Just an extra allocation(and for Rename, indirection) thats not needed.

clang-tools-extra/clangd/index/CanonicalIncludes.cpp

collectIWYUHeaderMaps(CanonicalIncludes *Includes) {
   private:
     CanonicalIncludes *const Includes;
   };
   return std::make_unique<PragmaCommentHandler>(Includes);
 }
 
 void CanonicalIncludes::addSystemHeadersMapping(const LangOptions &Language) {
   if (Language.CPlusPlus) {
-    static const auto *Symbols = new llvm::StringMap<llvm::StringRef>({
+    static const llvm::StringMap<llvm::StringRef> Symbols{
 #define SYMBOL(Name, NameSpace, Header) {#NameSpace #Name, #Header},
 #include "StdSymbolMap.inc"
         // There are two std::move()s, this is by far the most common.
         SYMBOL(move, std::, <utility>)
 #undef SYMBOL
-    });
-    StdSymbolMapping = Symbols;
+    };
+    StdSymbolMapping = &Symbols;
   } else if (Language.C11) {
-    static const auto *CSymbols = new llvm::StringMap<llvm::StringRef>({
+    static const llvm::StringMap<llvm::StringRef> CSymbols{
 #define SYMBOL(Name, NameSpace, Header) {#Name, #Header},
 #include "CSymbolMap.inc"
 #undef SYMBOL
-    });
-    StdSymbolMapping = CSymbols;
+    };
+    StdSymbolMapping = &CSymbols;
   }
 
   // FIXME: remove the std header mapping once we support ambiguous symbols, now
   // it serves as a fallback to disambiguate:
   //   - symbols with multiple headers (e.g. std::move)
   static const auto *SystemHeaderMap = new llvm::StringMap<llvm::StringRef>({
       {"include/__stddef_max_align_t.h", "<cstddef>"},
       {"include/__wmmintrin_aes.h", "<wmmintrin.h>"},

clang-tools-extra/clangd/refactor/Rename.cpp

 
 // By default, we exclude C++ standard symbols and protobuf symbols as rename
 // these symbols would change system/generated files which are unlikely to be
 // modified.
 bool isExcluded(const NamedDecl &RenameDecl) {
   if (isProtoFile(RenameDecl.getLocation(),
                   RenameDecl.getASTContext().getSourceManager()))
     return true;
-  static const auto *StdSymbols = new llvm::DenseSet<llvm::StringRef>({
+  static const llvm::DenseSet<llvm::StringRef> StdSymbols = {
 #define SYMBOL(Name, NameSpace, Header) {#NameSpace #Name},
 #include "StdSymbolMap.inc"
 #undef SYMBOL
-  });
-  return StdSymbols->count(printQualifiedName(RenameDecl));
+  };
+  return StdSymbols.contains(printQualifiedName(RenameDecl));
 }
 
 enum class ReasonToReject {
   NoSymbolFound,
   NoIndexProvided,
   NonIndexable,
   UsedOutsideFile, // for within-file rename only.
   UnsupportedSymbol,