* Compatible int32 and int64 for attr in op slice/strided_slice. test=develop

* Polish code in nn.py  test=develop

* Fix bug: set the same dtype for the inputs of elementwise_add. test=develop

* Convert int32 to int64 in slice op to avoid data overflow. test=develop

* Convert int32 to int64 in strided_slice_op to avoid data overflow. test=develop

* improve error reporting message

* fix some print transformer problems, test=develop

* simplify writing & avoid bud, test=develop

* polish detail, test=develop

* add base name alias; test=develop

* fix embedding bug; test=develop

* fix io error; test=develop

* add metric; test=develop

* add import palce; test=develop

* add setup; test=develop

* fix incubate reader; test=develop

* fix initializer error; test=develop

Add assert grammar for ProgramTranslator

* error message of cross_entropy_op, test=develop
* fix bug : can't use platform::errors::InvalidArgument in HOSTDEVICE, test=develop
* fix bug: recovery the check_variable_and_dtype for rank_loss and bpr_loss, test=develop

fix check info for flatten hash is_empty op; test=develop

* update err msg for dynamic_lstm and dynamic_lstmp, test=develop

* polish some sl api error message, test=develop

* polish python input check of stride slice, test=develop

* fix unittest bugs, test=develop

* fix bug with `if Tensor` in is_control_flow test=develop

* remove continue test=develop

* enhance rank_loss error message, test=develop

* enhance similarity_focus error message, test=develop

* enhance squeeze error message, test=develop

* add scale_x_y for yolo_box, test=develop

* refine eps in iou_similarity, test=develop

* fix error log: resahpe, range, reverse.

* test=develop add linear interpolate operator

* Remove the error in the elementwise op, use the backup mode to calculate

* fix bug of cross_entropy_loss,test=develop
* fix log_softmax and some comment,test=develop

* support save_inference_model in program_translator test=develop

* fix compatibility with OrderedDict.values() in python3 test=develop

* synchronized random_seed test=develop

* Polish Error Message test=develop

* copy dygraph api to paddle.imperative, test=develop

* polish the code, test=develop

* polish code, test=develop

* polish code, test=develop

* move paddle.imperative.Layer to paddle.nn.Layer, test=develop

* [Dy2Stat] Add test for bert pretraining. 

* Construct fake data. 

* Synchronous random seed of program. 

* fix numpy ndarray mul var base error; test=develop

* add comment for __array_ufunc__ ; test=develop

* move unitest from imperative math op path to test_math_op_patch_var_base;
test=develop

* raise index error when slice out of range; test=develop

* add uni test; test=develop

* fix format error; test=develop

* add comment for py::index_error; test=develop

* polish error message; test=develop

* polish error message; test=develop

* support to train in static

* support to independent decorator

* remove in_dygraph_mode condition in ProgramTranslator

* fix import param_guard and add train/eval test=develop

* Modify into ShareVarsFromScope and rm __all__ in partial_program test=develop

1. To make ProgramTranslator to support `assert` grammar, this PR adds `assert` python API and C++ code. 

2. Fix a bug: graph_pattern_detector.h #include <gtest/gtest_prod.h> but didn't declared dependency at CMakeLists, which can cause single build failure.

3. Refactoring `Formatter` in print_op to make it reusable and reuse the formatter to print in assert op.

* fix error message, test=develop

* add unittest, test=develop

* API/OP (margin_rank_loss, nce, row_conv, glu, positive_negative_pair) error message enhancement, test=develop

* add unittest for glu, test=develop

* Replace dygraph_to_static_func with @declarative or program_translator.get_func in test_list.py

* Add comments in ConditionalBlock.

* Support list pop last item. 

* Support pop the i-th item. 

* Support an empty tensor array as Input in assign op and set the kernel type is float.

* update dygraph.rnn import

* update dygraph.rnn import

* change unit to cell

* fix math equations

* fix math equations

* fix examples

* remove unused import

* fix examples

* fix error info for rnn related api

* passed local test, test=develop

* double check the code

* double check the code, test=develop

* update 'shape' check in RNNCell, test=develop

* add long dtype to RNNCell

* fix long type in python3
Co-authored-by: NXingWu01 <wuxing@iie.ac.cn>

test=develop

* add timeout and http store in communication, add revert and confirm in fleet
* test=develop

* Move complex into dir incubate, test=develop

* Fix imports, test=develop

* Fix docs, test=develop

* Forbid import functions from paddle.incubate directly, test=develop

Add the pslib graph batch reader mode, add the test case for this change

* Support LoDTensorArray for slice op.
* Support read elements of list in dygraph_to_static
* Fix infershape add test for infershape.
* Support Tensor for Attr(starts) and Attr(ends). 
* Use new interfaces in VarTypeInference.