* Move BasicApiTransformer to a separate file. test=develop

* Fix a bug: A api in module is not a real dygraph api in dygraph_to_static. test=develop

* improve efficiency of dot op in dygraph mode

* add comments for dot op for dygraph behavior

* fix trt fc fuse test, test=develop

* fix trt_transpose_flatten_concat shape, test=develop

* add addcmul, test=develop

* OP clip, merge_lod_tensor, convert/elementwise error message enhancement. test=develop

test=develop

As the title

* use 32 bit index to improve expand op, test=develop

* remove redundant code, test=develop

* add nll_loss op test=develop

* Weight quantization support channel_wise_abs_max method to achieve higher accuracy

* add paddle.std api test=develop

* update  test=develop

* fix example code format test=develop

* allow amp and recompute working together

API/OP (center_loss, fluid.one_hot, prroi_pool, roi_pool, ctc_greed_decoder) error message enhancement (#23794)

* error message enchanced, test=develop

* error message enchanced for APIs, test=develop

* error message enhanced for roi_pool, test=develop

* update added code, test=develop

* update fluid/input.py, test=develop

* update fluid/input.py ,test=develop

* fix code style, test=develop

* fix lower converage, test=develop

* error message enhanced for roi pool, test=develop

Correct the name [`FLAGS_sync_nccl_allreduce`](https://www.paddlepaddle.org.cn/documentation/docs/zh/advanced_guide/flags/others_cn.html#flags-sync-nccl-allreduce) based on the information from our official website.

As the title.

* fix bug in reduce op test=develop

* fix bug in reduce op test=develop

* API(fused_embedding_fc_lstm) error message enhancement. test=develop

C++ API enhancement.

* Refine code, test=develop

* Refine code. test=develop

Enhance print op c++ error message.

* error message enhancement create_parameter create_global_var, test=develop

* use six.PY2 to use long, test=develop

* fix input dtype for create_parameter, test=develop

Fix the compile problem in norm op in the windows env, add delete some invalid argument 

* refine error message, test=develop

* fix judge pslib & ranspiler

* enhance the error message of box_coder, test=develop

* enhance error message in box_decoder_and_assign

* enhance error message of collect_fpn_proposals

* enhance errror message of distribute_fpn_proposals

* enhance error message of multiclass_nms, test=develop

* add nn.interpolate, test=develop

* fix interpolate typo, test=develop

* formate code, test=develop

* fix unitest, test=develop

* add test layers, test=develop

* add test layers, test=develop

* extract common function, test=develop

* reduce the threads for cuda10, test=develop

* update unitest, test=develop

* polish unitest, test=develop

* add dygraph test, test=develop

* format description, test=develop

* add 5D input check, test=develop

* fix doc, test=develop

* enrich count enforce scripts, test=develop, test=document_fix

* add usage & result, test=develop, test=document_fix

test=develop