* rewrite the sigmoid_focal_loss code example. test=develop

* fix spelling mistake in comments of code example.test=develop

* [dy2stat] Support len

* add convert_call func

* refine code test=develop

* support NHWC in Pool2D, test=develop

* add unittest, test=develop

* fix unittest, test=develop

* fix typo, test=develop

* follow comments, test=develop

* refine comments, test=develop

* test=develop update interpolate & upsample api

API/OP(sequence_first_step, sequence_last_step, sequence_mask, beam_search, beam_search_decode) error message enhancement (#24590)

* Support to create LoDTensorArray in control flow (cond and while_loop)

* Fix bug: return LoDTensorArray in while_loop

* Change code in list_transformer.py to accommodate the new features. 

* API/OP(sequence_expand_as) error message enhancement.
test=develop
Co-authored-by: NFrostML <380185688@qq.com>

* dynamic_gru err_msg enhancement, test=develop

* chunk_eval err_msg enhancement and fix crf_decoding output type, test=develop

* BeamSearchDecoder err msg enhancement, test=develop

* fix doc for chunk_eval, test=develop

* refine lod err msg for chunk_eval, test=develop

* 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

* test=develop, test=document_fix

* test=develop, test=document_fix
Co-authored-by: Nswtkiwi <1208425345@qq.com>

* fix error message, test=develop

* 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 error check of stack and space_to_depth
* test=develop

* Format error message for ops, test=develop

* Fix check in sequence_expand, test=develop

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

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

test=develop

Fix the elementwise_ops axis bug, make elementwise_ops has the same the op function for override ops

* polish some sl api error message, test=develop

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

* fix unittest bugs, 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

* fix rnn check_type list error

* tigger ci, test=develop

* update modify, 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.

目前在while_loop的执行过程中，loop_vars中的变量在每次的循环中都会进行拷贝，但是LoDTensorArray类型的变量在while循环体中已经完成了读/写的操作，即完成了更新，此时在进行拷贝属于冗余的操作，故该PR跳过每次循环中loop_vars中LoDTensorArray类型的变量的复制过程。

在PaddleCV/ocr_recognition/atention模型的预测过程中进行性能测试：
|性能|with this PR|without this PR|提升|
|---|---|---|---|
|速度|4957.4ms|4978.47ms|0.4%|

* 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.

* 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

* enhance add_position_encoding error message, test=develop

* enhance warpctc & scaled_dot_product_attention error message, test=develop

* modified error message and ctest of scaled_dot_product_attention, test=develop