message: [XLA:Python] Fix segfault in PyLocalBuffer::Release.
  According to phawkins@, this sometimes works due to differences in how
  different compilers order the .get() and .release() calls. Many thanks
  to phawkins@ for figuring this out!
diff: @@ -774,10 +774,10 @@ StatusOr<std::shared_ptr<SharedDeviceBuffer>> PyLocalBuffer::Release(
  }
  }
  if (block_stream != nullptr) {
  + se::Stream* block_stream_ptr = block_stream.release();
  local_device_state->ThenExecuteOnCallbackThread(
  - block_stream.get(),
  - [device_buffer, block_stream_ptr{block_stream.release()},
  - local_device_state]() {
  + block_stream_ptr,
  + [device_buffer, block_stream_ptr, local_device_state]() {
  local_device_state->ReturnStreamToPool(
  std::unique_ptr<se::Stream>(block_stream_ptr));
  });
  