Simple code clean up

remove eigen threadpool for the speed up

* test=develop, optimize global_step

* refactor momentum op to combine weight_decay (scale op and sum op)

Adding uint8 support for squeeze operator.

* Add bf16 matmul, fc, elementwise add and mul

* Correct unit test

* 1.add xpu slice op 2. add xpu top_k op 3.modify xpu cast to new api

* 1.add xpu slice op 2. add xpu top_k op 3.modify xpu cast to new api

* add lstm, simple rnn op kernel

* fix the test_lstm for the rnn op

* change func name

* fix forward postprocess bug

* add gru forward, backward code

* remove unittest.skipIf; use a big rnn op instead of combination op

* fix input doesn't have gradient bug

* add eigen lstm forward, backward
Co-authored-by: Nwawltor <fangzeyang0904@hotmail.com>

* adjust kunlun header file
*test=kunlun

* update kunlun unittest
*test=kunlun

* update xpu unitest
* test = kunlun

* update xpu unittest
* test=kunlun

* update xpu unitest
* test=kunlun

* Add multi_gru op and tests

* removed redundant disable_dygraph()

Add new operator log10

test=develop

* add unittest and check unittest for windows

* fix lstm OP compile error on windows

Co-authored-by: Nyaoxuefeng6 <yaoxuefeng@baidu.com>

fix the gradient bug for the topk v2 

* Add checkpoint to quantize

* Change bfloat16 option

* Fix gradients with ignore_idx in softmax_with_cross_entropy.
test=develop

* Fix gradients with ignore_idx in softmax_with_cross_entropy on cpu.
Remove softmax_with_cross_entropy from op_threshold_white_list.
test=develop

* Fix test_softmax_cross_entropy_op.py.
test=develop

* register op_version for addto

* upgrade pass capability

* change eq to le

* change eq to le

* fix merge

* update, test=develop

register the op version for some ops

* make Numpy version is below 1.19.3

* fix 2.0 doc

* skip_layernorm_op done

* add unittest

* slice op convertor support trt < 6

* skip_layernorm only work in ernie

As the title