* add sendrecv, test=develop

* clear CUDA compile environment on windows

* fix Windows CI

* fix Windows CI

* fix Windows CI

* new optimize for where_index_op with prefix sum version.

* write a scan prefix sum kernel with stream for where index op.

* optimize where_index by using cub::DeviceScan::InclusiveSum instead of imperfect self-kernel.

* remove CheckTrue struct and rename stide_array for readable.

* optimize variable name for readable.

* optimize function name and annotation.

* optimize pull sparse

* optimize pull sparse

* change macro

* format

* fix bn docs

* fix unittest

A follow up PR of #32420, we changed the doc of python/paddle/fluid/layers/tensor.py in that PR and we are changing python/paddle/tensor/creation.py in this PR.

* Modified params of some APIs to support tuple and list.

* fixed bug.

* Modified the return value of tensor.grad from numpy as tensor.

* Modify unittests.

* fixed bugs.

* Add warning info for x.grad

* fixed unittests which used x.grad

* fixed bug.

* fix dataloader exit error if user exit program when dataloader is still iterating. test=develop

* Unset ReserveSpace for inference program.

* Support training from an inference program.

* change prepend to append

* fix ut

* add testcase

* fix ut

* fix test_custom_relu_model

* fix model parallel

* rm parallel_help.py

* add embedding

* support backward return None.

* edit unittest.

* edit code according to CI

* Improve error information

* optimize slice op and slice grad op, test=develop

* optimize variable name and annotation information, test=develop

* skip op has no fp16 kernel

* add ut

* add norm_by_times param to ctc_loss

* fix doc,test=develop

paddle.to_tensor will be translated to paddle.assign in Dy2stat, however paddle.assign doesn't support int, float, bool. This PR added the supports.

* [DOC] Clarify the difference between paddle.norm and np.linalg.norm

* add pp dygraph, test=develop

* Dygraph reocmpute

* unitest for Dygraph reocmpute

* dy recompute remove unitest for win and mac

`range` API set its output shape in dygraph but not in static graph, which can cause Dy2stat error. This PR set the shape of `range` API when possible.

* fix airank bert emb order

* move input num check to converter

* add input num check

* add unused var check white list

* update testcases

* remove unused codes

* update the docstring for samcd_processor

* no need to import the six module

* 我也不知道为何有一个前导空格，但现在有单元测试，取消这个空格没啥问题

* add unittests for print_signatures; add the first case for 'required' mechanism when executing sample code testing

* there is no paddle installed in PR-CI-APPROVAL

test=document_fix

* support python39 and delete python35

* support python39 in Dockerfile.centos

* fix ubuntu18 bug

* update Dockerfile.ubuntu setuptools

* fix centos py39 errors

* fix centos py39 error2