* [CustomDevice] add pipeline parallel support

* update

* update

* [CustomDevice] add c_identity op

* fix use calc stream

* Delete the /paddle/fluid/platform/device/npu directory

* clear Cmakelists

* Try removing npu in the header file

* [CustomDevice] fix SyncDefaultStream for process_group_custom

* update

* add UpdateWaitChain for  process_group_custom

* add UpdateWaitChain for  process_group_custom

* [CustomDevice] fix process_group_custom api

* update

* update

* update

* update

* comm_context and static init

* refactor: move to phi/core/distributed

* refactor: avoid mutable_data usage

* fix: windows sock

* fix: device without nccl
Co-authored-by: Wen Sun <syl1887415157@126.com>

* refactor: use base class

* fix: incorrect deps

* fix: add missing header

* refactor: update class structures

* fix: bkcl typo

* fix: remove redundant def

* refactor: update pg custom

* fix: use new api in ut

* fix: typo

* revert: recover legacy apis

* fix: add GetDeviceContext

* refactor: simplify send, recv interfaces

* refactor: rm send_partial, recv_partial, all_gather_partial

* [CustomDevice] GetCCLComm add custom device support

* update

* update

* update

* [CustomDevice] add custom ccl 2/2

* update

* update

* update launch

* add pg_hccl

* add processgroup_nccl