message: [PJRT] Increase minimum thread stack size for HostStream threads to 8MiB, which was the previous default on Linux.
  2MiB stacks were causing segfaults in the JAX linear algebra tests on Linux, which call into LAPACK/OpenBLAS.
diff: @@ -43,8 +43,10 @@ StatusOr<std::shared_ptr<PjRtClient>> GetCpuClient(bool asynchronous) {
  for (int i = 0; i < client->device_count(); ++i) {
  se::StreamExecutorConfig config;
  config.ordinal = i;
  + // 8MiB stacks seem to be necessary for running LAPACK/OpenBLAS
  + // computations.
  config.device_options.non_portable_tags["host_thread_stack_size_in_bytes"] =
  - absl::StrCat(2048 * 1024);
  + absl::StrCat(8192 * 1024);
  TF_ASSIGN_OR_RETURN(se::StreamExecutor * executor,
  platform->GetExecutor(config));
  auto device_state = absl::make_unique<LocalDeviceState>(
  