* Add new api: is_tensor

* Add new api: is_tensor

* Add new api: is_tensor

* Add new api: is_tensor

* Add build paddle inference;test=document_fix

* Add build paddle inference;test=document_fix

* fix generate_proposal_labels in cascade-rcnn series model, test=develop

* fix example code & unittest, test=develop

* update code from review comments, test=develop

* fill_constant supports nan and inf

* add ut

* add pil backend

* refine code of DygraphToStaticAst

* add __init__ function

* add stack pool2d roi_align xpu op,test=kunlun

* error message opt, test=kunlun

* add xpu unittest,test=kunlun

* skip check grad,test=kunlun

* fix boostget , test=kunlun

* error message opt for XPU, test=kunlun

* add rois_num for roi_align xpu OP, test=develop

* cat exeception in request download; test=develop

* add re-try in download; test=develop

* fix dataloader

* Add zhhsplendid into PE approver, test=develop

* Fix /tab, space mix usage

* Add AVX512 instruction check for C-API

* Fix formatting

* lookup_table_v2_op_xpu report errors;test=kunlun

* lookup_table_v2_op_xpu report errors;test=kunlun

* lookup_table_xpu op report errors;test=kunlun

* add adam xpu op;test=kunlun

* reset lookup

* change adam wrong;test=kunlun

* hapi/model step learning rate on batch end. test=develop

* fix error message,test=kunlun

* fix, test=kunlun

Fix diag OP bug on Windows Python3.8 ，remove the std::min

fleet support paddle.optimzier

* bug fix

* fix fleet_base

* bug fix

* fix coverage

* add doc, test=document_fix

* transfer from paddle.fluid.layers.assign() into creation.py,test=develop

* fix ut fail,add support for paddle.assign,test=develop

* fix,test=develop

* fix UT coverage,test=coverage

* fix UT fail,test=coverage

* fix doc,test=develop

* Still has bugs.

* Fixed allclose_op bug, which cannot deal with some cases of fp64 inputs.

* improved CUDA kernel performance.

* Changed CUDA code.

* Fixed a bug in cuda kernel which cannot deal with large dimension input, and added an unittest for it.

* Add a test case for float32 input.

* fix multinomial doc

* fix multinomial error message

* little doc change

* fix Categorical class doc

* optimize format of error message

* fix CPU Kernel error message format

* fix isinf and isnan error in WindowsOPENBLAS CI

* delete inf and nan

* add manual_seed in sample code

* little error message change

* change error message to InvalidArgument

* add full point for error message and add manual_seed in CPU environment

* add stack pool2d roi_align xpu op,test=kunlun

* error message opt, test=kunlun

* add xpu unittest,test=kunlun

* skip check grad,test=kunlun

* fix boostget , test=kunlun

* error message opt for XPU, test=kunlun