message: Fix NetBSD build for llvm r322475
diff: @@ -871,13 +871,13 @@ NativeProcessNetBSD::GetAuxvData() const {
  */
  size_t auxv_size = 100 * sizeof(AuxInfo);
  - ErrorOr<std::unique_ptr<MemoryBuffer>> buf =
  + ErrorOr<std::unique_ptr<WritableMemoryBuffer>> buf =
  llvm::MemoryBuffer::getNewMemBuffer(auxv_size);
  struct ptrace_io_desc io;
  io.piod_op = PIOD_READ_AUXV;
  io.piod_offs = 0;
  - io.piod_addr = const_cast<void *>(static_cast<const void *>(buf.get()->getBufferStart()));
  + io.piod_addr = static_cast<void *>(buf.get()->getBufferStart());
  io.piod_len = auxv_size;
  Status error = NativeProcessNetBSD::PtraceWrapper(PT_IO, GetID(), &io);
  @@ -888,7 +888,7 @@ NativeProcessNetBSD::GetAuxvData() const {
  if (io.piod_len < 1)
  return std::error_code(ECANCELED, std::generic_category());
  - return buf;
  + return std::move(buf);
  }
  Status NativeProcessNetBSD::ReinitializeThreads() {
  