* add histc operator, test=develop

* update english doc to 2.0 API, test=develop

* update API from histc to histogram, test=develop
Co-authored-by: Nroot <root@yq01-gpu-255-129-15-00.epc.baidu.com>

* Post_training_quantization supports optimize model by fusing, test=develop

Enhance error message of checkpoint_notify_op, fake_init_op gen_nccl_id_op and listen_and_serv_op (#24554)

test=develop

* Add isCached() mechanism for BatchNorm and LRN oneDNN operators
test=develop

* Formatting fix
test=develop

The PR: https://github.com/PaddlePaddle/Paddle/pull/24651 seems causes new random failure of unit test test_parallel_executor_seresnext_base_cpu. The reason is that smaller batch size causes random optimization of neural network. I distinguished cpu/gpu batch size to fix the unittest.

* add SetCommandLineOption

* add the print_FLAGS function

* remove the test demo

* modify the location of macro

* add the 'WITH_STATIC_LIB' option on windows

* modify the macro of PD_INFER_DECL

* modify the the fuction name

* modify the unittest

* modify the code style

replace join to terminate

* support nested input and output test=develop

* remove code of convert type(output) in unittest test=develop

* add warning test=develop

* Add IsRuntime judgement in GRUUnit test=develop

* add IsRuntime judgement is GradOp test=develop

* Refine Error Message of SelecteInput/Output test=develop

* refine Error Message of RNNMemoryHelperOp test=develop

添加loss自适应的学习率衰减策略。

test=develop
test=document_fix

* append error op hint for grad op maker, test=develop

* add unittests for coverage, test=develop

* Fix bug of different dtype in dygraph math_op_patch, test=develop

* support np.dtype and str, test=develop

* add unit test, test=develop