[NFC] Initialize class member pointers to nullptr.

  SourceRange Range;

  mutable StringRef RawText;

  mutable const char *BriefText;

  mutable const char *BriefText = nullptr;

  mutable bool RawTextValid : 1;   ///< True if RawText is valid

  mutable bool BriefTextValid : 1; ///< True if BriefText is valid

  class redecl_iterator {

    /// Current - The current declaration.

    decl_type *Current = nullptr;

    decl_type *Starter;

    decl_type *Starter = nullptr;

    bool PassedFirst = false;

  public:

  CodeGenerator *getCodeGenerator() const;

  BackendConsumer *BEConsumer;

  BackendConsumer *BEConsumer = nullptr;

};

class EmitAssemblyAction : public CodeGenAction {

class HLSLExternalSemaSource : public ExternalSemaSource {

  Sema *SemaPtr = nullptr;

  NamespaceDecl *HLSLNamespace = nullptr;

  CXXRecordDecl *ResourceDecl;

  CXXRecordDecl *ResourceDecl = nullptr;

  using CompletionFunction = std::function<void(CXXRecordDecl *)>;

  llvm::DenseMap<CXXRecordDecl *, CompletionFunction> Completions;

  class DelayedDiagnostics;

  class DelayedDiagnosticsState {

    sema::DelayedDiagnosticPool *SavedPool;

    sema::DelayedDiagnosticPool *SavedPool = nullptr;

    friend class Sema::DelayedDiagnostics;

  };

  typedef DelayedDiagnosticsState ParsingDeclState;