* refine dist train RPC deps

* clean up

* clean up

* fix ut

* remove input for fetch_barrier

* follow comments

fix a few other things

* dist transpiler add control dependency var between send and recv

* fix async deps

* follow comments and refine

* fix deps connect for rpc ops

* make fc fuse work with ditu rnn
* add ditu rnn data download to CMAKE

* link IR graph to analysis graph

* add clean code and update

* add infer_clean_pass

* add ir_pass_manager

* support fc fuse executation

* fix ir circle

Port dist_transpiler new added codes
Port ut for clone desc

when while_grad, it writes multiple @EMPTY@ with no VarDesc.

* Add write after write

* follow comment

add doc