message: Add debug information to DSR CHECK.
  Summary: Often the pointer can be hard to get back because Clang apparently can't produce DWARF symbols.
diff: @@ -3678,9 +3678,9 @@ QuicSocket::WriteResult QuicTransportBase::setDSRPacketizationRequestSender(
  }
  if (stream->dsrSender != nullptr) {
  // If any of these aren't true then we are abandoning stream data.
  - CHECK_EQ(stream->writeBufMeta.length, 0);
  - CHECK_EQ(stream->lossBufMetas.size(), 0);
  - CHECK_EQ(stream->retransmissionBufMetas.size(), 0);
  + CHECK_EQ(stream->writeBufMeta.length, 0) << stream;
  + CHECK_EQ(stream->lossBufMetas.size(), 0) << stream;
  + CHECK_EQ(stream->retransmissionBufMetas.size(), 0) << stream;
  stream->dsrSender->release();
  stream->dsrSender = nullptr;
  return folly::unit;
  