Kill unused variable m_tu_decl_up in SymbolFilePDB

[lanza]

Summary

An TranslationUnitDecl was being brought in from the clang::ASTContext
which required clang specific code to exist in SymbolFilePDB.
Since it was unused we can just get rid of it along with the clang
specific code.

[lanza]

rebase

source/Plugins/SymbolFile/PDB/SymbolFilePDB.h

private:
   llvm::DenseMap<uint64_t, std::string> m_public_names;
 
   SecContribsMap m_sec_contribs;
 
   std::vector<lldb::TypeSP> m_builtin_types;
   std::unique_ptr<llvm::pdb::IPDBSession> m_session_up;
   std::unique_ptr<llvm::pdb::PDBSymbolExe> m_global_scope_up;
   uint32_t m_cached_compile_unit_count;
-  std::unique_ptr<lldb_private::CompilerDeclContext> m_tu_decl_ctx_up;
 
   lldb_private::UniqueCStringMap<uint32_t> m_func_full_names;
   lldb_private::UniqueCStringMap<uint32_t> m_func_base_names;
   lldb_private::UniqueCStringMap<uint32_t> m_func_method_names;
 };
 
 #endif // lldb_Plugins_SymbolFile_PDB_SymbolFilePDB_h_

source/Plugins/SymbolFile/PDB/SymbolFilePDB.cpp

 
 lldb_private::SymbolFile *
 SymbolFilePDB::CreateInstance(lldb_private::ObjectFile *obj_file) {
   return new SymbolFilePDB(obj_file);
 }
 
 SymbolFilePDB::SymbolFilePDB(lldb_private::ObjectFile *object_file)
     : SymbolFile(object_file), m_session_up(), m_global_scope_up(),
-      m_cached_compile_unit_count(0), m_tu_decl_ctx_up() {}
+      m_cached_compile_unit_count(0) {}
 
 SymbolFilePDB::~SymbolFilePDB() {}
 
 uint32_t SymbolFilePDB::CalculateAbilities() {
   uint32_t abilities = 0;
   if (!m_obj_file)
     return 0;
 

 
 void SymbolFilePDB::InitializeObject() {
   lldb::addr_t obj_load_address = m_obj_file->GetBaseAddress().GetFileAddress();
   lldbassert(obj_load_address && obj_load_address != LLDB_INVALID_ADDRESS);
   m_session_up->setLoadAddress(obj_load_address);
   if (!m_global_scope_up)
     m_global_scope_up = m_session_up->getGlobalScope();
   lldbassert(m_global_scope_up.get());
-
-  TypeSystem *type_system =
-      GetTypeSystemForLanguage(lldb::eLanguageTypeC_plus_plus);
-  ClangASTContext *clang_type_system =
-      llvm::dyn_cast_or_null<ClangASTContext>(type_system);
-  lldbassert(clang_type_system);
-  m_tu_decl_ctx_up = llvm::make_unique<CompilerDeclContext>(
-      type_system, clang_type_system->GetTranslationUnitDecl());
 }
 
 uint32_t SymbolFilePDB::GetNumCompileUnits() {
   if (m_cached_compile_unit_count == 0) {
     auto compilands = m_global_scope_up->findAllChildren<PDBSymbolCompiland>();
     if (!compilands)
       return 0;