message: [HostNativeThreadBase] Undo nullptr changes
  The thread result type is an unsigned instead of a pointer on windows,
  so we shouldn't replace 0 with nullptr here.
diff: @@ -18,10 +18,10 @@ using namespace lldb;
  using namespace lldb_private;
  HostNativeThreadBase::HostNativeThreadBase()
  - : m_thread(LLDB_INVALID_HOST_THREAD), m_result(nullptr) {}
  + : m_thread(LLDB_INVALID_HOST_THREAD), m_result(0) {}
  HostNativeThreadBase::HostNativeThreadBase(thread_t thread)
  - : m_thread(thread), m_result(nullptr) {}
  + : m_thread(thread), m_result(0) {}
  lldb::thread_t HostNativeThreadBase::GetSystemHandle() const {
  return m_thread;
  @@ -37,7 +37,7 @@ bool HostNativeThreadBase::IsJoinable() const {
  void HostNativeThreadBase::Reset() {
  m_thread = LLDB_INVALID_HOST_THREAD;
  - m_result = nullptr;
  + m_result = 0;
  }
  bool HostNativeThreadBase::EqualsThread(lldb::thread_t thread) const {
  @@ -47,7 +47,7 @@ bool HostNativeThreadBase::EqualsThread(lldb::thread_t thread) const {
  lldb::thread_t HostNativeThreadBase::Release() {
  lldb::thread_t result = m_thread;
  m_thread = LLDB_INVALID_HOST_THREAD;
  - m_result = nullptr;
  + m_result = 0;
  return result;
  }
  