Support to transformfor ele in var stms in which var is a slice of Tensor.

* delete no need to calculate inputs in dygraph op_test

* delete no need to calculate inputs in dygraph op_test

Before this commit, test_slice use old api `dygraph_to_static_func` to use Dynamic-t-Static and use Executor explicitly，which is not recommended to users.
After fixed, use recommended API `paddle.jit.to_static` to replace `dygraph_to_static_func`, which won't trigger the random exception on coverage CI.

fix isfinite_v2_op OpProtoAndCheckerMaker AddComment bug 

Unit test reported memory not enough on CPU machines. Reduce batch size again.

* update to_tensor en docs

* add conj op for complex types

* add conj for complex types

* add more test case

* add conj_op test

* modify conj api and impl

* add complex type for fill_constant_op xpu

* add setConstant for complex type

* remove complex conj test file

* user define grad for test_conj_op

* add test case for static mode of conj api

* modify conj doc

* change input args name to x

* remove useless codes

* conj support real types

* add conj test case for real number

* enable_use_gpu has higher priority than FLAGS

* update.

* Windows generate pdb and dump, for debug

* fix code style, test=develop

* modify cmakelist

Modify CublasHandleHolder from using PADDLE_ENFORCE_CUDA_SUCCESS to PADDLE_RETRY_CUDA_SUCCESS to fix random unittest failure. We checked that the unittest log showed CUDA allocation error at this file, which may due to GPU not enough. We fixed similar failure in the past, so we applied PADDLE_RETRY_CUDA_SUCCESS here.

* add complex real op & api & unittest

* add imag op & api & unittest

* refactor op impl

* revert simplify writing due to complile failed

* polish details

* polish grad op code

* update EarlyStopping doc

* update EarlyStopping doc, test=document_fix

* Add approval monitor for unity_build_rule.cmake, test=develop

* fix words spell error, test=document_fix

* fix expand && concat/transpose to new api

* update xpu_header

* update activation op on kunlun

* update activation op on kunlun

* update activation op on kunlun

* update activation op on kunlun

* update activation op on kunlun

* add nearest_interp on kunlun

* update error message

* add constant pad double grad

* 添加rocm平台支持代码

* 修改一些问题

* 修改一些歧义并添加备注

* 修改代码格式

* 解决冲突后的代码修改

* 修改operators.cmake

* 修改格式

* 修正错误

* 统一接口

* 修改日期

* add static.amp into setup.pu.in

* add unittest for api

* improve grad perf

* fix wmt14 doc, remove backward, add bidirect direction in rnn api

* fix rnn unittest

* fix test_rnn_nets_static.py bug

* added UT should not exceed 15s

* fix error

* UT limit of 15s is the first to be executed

* fix error

* fix error with CI_SKIP_CPP_TEST

* modfied tiemout setting

* fix error

* add op test case for complex

* polish code details

* add xpu set constant support

* fix argument rror

* remove useless pyc file

* add transpose double grad test=develop

* add alias for fluid.contrib.mixed_precision