[CodeGen] Remove unused declaration/function GetOrCreateRTTIProxyGlobalVariable

[kazu]

Summary

The last use removed by:

commit 46f366494f3ca8cc98daa6fb4f29c7c446c176b6
Author: Fangrui Song <[e-mail]>
Date:   Sat May 20 08:24:20 2023 -0700

This patch also removes RTTIProxyMap, which becomes unused once I
remove GetOrCreateRTTIProxyGlobalVariable.

clang/lib/CodeGen/CodeGenModule.h

private:
   /// Mapping from canonical types to their metadata identifiers. We need to
   /// maintain this mapping because identifiers may be formed from distinct
   /// MDNodes.
   typedef llvm::DenseMap<QualType, llvm::Metadata *> MetadataTypeMap;
   MetadataTypeMap MetadataIdMap;
   MetadataTypeMap VirtualMetadataIdMap;
   MetadataTypeMap GeneralizedMetadataIdMap;
 
-  llvm::DenseMap<const llvm::Constant *, llvm::GlobalVariable *> RTTIProxyMap;
-
   // Helps squashing blocks of TopLevelStmtDecl into a single llvm::Function
   // when used with -fincremental-extensions.
   std::pair<std::unique_ptr<CodeGenFunction>, const TopLevelStmtDecl *>
       GlobalTopLevelStmtBlockInFlight;
 
 public:
   CodeGenModule(ASTContext &C, IntrusiveRefCntPtr<llvm::vfs::FileSystem> FS,
                 const HeaderSearchOptions &headersearchopts,
public:
   /// Return a vector of most-base classes for RD. This is used to implement
   /// control flow integrity checks for member function pointers.
   ///
   /// A most-base class of a class C is defined as a recursive base class of C,
   /// including C itself, that does not have any bases.
   std::vector<const CXXRecordDecl *>
   getMostBaseClasses(const CXXRecordDecl *RD);
 
-  llvm::GlobalVariable *
-  GetOrCreateRTTIProxyGlobalVariable(llvm::Constant *Addr);
-
   /// Get the declaration of std::terminate for the platform.
   llvm::FunctionCallee getTerminateFn();
 
   llvm::SanitizerStatReport &getSanStats();
 
   llvm::Value *
   createOpenCLIntToSamplerConversion(const Expr *E, CodeGenFunction &CGF);
 

clang/lib/CodeGen/CodeGenModule.cpp

if (RD->getNumBases() == 0)
       MostBases.insert(RD);
     for (const CXXBaseSpecifier &B : RD->bases())
       CollectMostBases(B.getType()->getAsCXXRecordDecl());
   };
   CollectMostBases(RD);
   return MostBases.takeVector();
 }
 
-llvm::GlobalVariable *
-CodeGenModule::GetOrCreateRTTIProxyGlobalVariable(llvm::Constant *Addr) {
-  auto It = RTTIProxyMap.find(Addr);
-  if (It != RTTIProxyMap.end())
-    return It->second;
-
-  auto *FTRTTIProxy = new llvm::GlobalVariable(
-      TheModule, Addr->getType(),
-      /*isConstant=*/true, llvm::GlobalValue::PrivateLinkage, Addr,
-      "__llvm_rtti_proxy");
-  FTRTTIProxy->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
-
-  RTTIProxyMap[Addr] = FTRTTIProxy;
-  return FTRTTIProxy;
-}
-
 void CodeGenModule::SetLLVMFunctionAttributesForDefinition(const Decl *D,
                                                            llvm::Function *F) {
   llvm::AttrBuilder B(F->getContext());
 
   if ((!D || !D->hasAttr<NoUwtableAttr>()) && CodeGenOpts.UnwindTables)
     B.addUWTableAttr(llvm::UWTableKind(CodeGenOpts.UnwindTables));
 
   if (CodeGenOpts.StackClashProtector)