* fix double grad visitid unit; test=develop

* change name hash_pair to HashPair; test=develop

* follow comment; test=develop

* Remove the output for moving_average_abs_max_scale op, test=develop

* refine strategy compiler and meta optimizers
make async as a_sync

* unified signal error format

* refine signal error message

* remove ProgramTranslator.save_inference_model

* adapt save_quantized_model

* revert buffer check implemention

* remove useless import function

* simplify buffered reader to improve DataLoader performance

* fix 22 failed unittests

* fix cuda pinned context condition

* fix test_reader_reset failed

* fix two failed unittests

* change unittest place

* polish error messaage

* polish cast op GetExpecctedKernelType

* remove debug info in unittest

* add more settings for distributed strategy
Basically, DistributedStrategy has several parts of configurations:
- BuildStrategy: the same as paddle.fluid.BuildStrategy, but the distributed arguments are moved out of BuildStrategy
- ExecutionStrategy: the same as paddle.fluid.ExecutionStrategy
- collective communication configs: nccl_comm_num, hierarchical allreduce and so on
- distributed algorithms: async_update(mainly used in PS), lars, lamb and so on

* polish framework error message part3

* polish details

* fix error message print error

* Added DNNL cache management for DyGraph

* move FLAGS_use_mkldnn to more general CMakeLists, getu use of the flag in ClearGradients

* missing file

* Fixes after review

* Bringing back original idea of place for 'use_mkldnn' flag to be accessible from platform nad imperative.

* Removed duplicate and added docs

* Fixes for CI

* fix the double grad bug for the star gan. test=develop

* update the retain_graph parameter doc. test=develop

* add the unit test for the retain_graph parameter. test=develop

* polish framework error meg part2

* polish details

* fix error msg report in ir/, about 19 files, test=develop

* modified some unclear descriptions, test=develop

* modified some unclear descriptions, test=develop

* modify unit test pass_test.cc, because the error report in pass.cc is used by pass_test.cc, test=develop

* refine squeeze, test=develop

* update squeeze, test=develop

* refine compile-time infershape, test=develop

* add more unittest, test=develop

* follow comments, test=develop

* add update_api, test=develop

* follow comments, test=develop

test=develop

* New features, add sinh and cosh op, test=develop

* remove duplicate test function and remove out paramters, test=develop

* Add out paramters temporary, remove later. test=develop

* remove out args, PR 25570, test=develop

* remove TestParameter, test=developx

* add test api for static dygraph, test=develop

* add backword unittests for sinh and cosh, test=develop

add fp64 support in sequence_pool, test=develop

* fix best_fit_allocator_test on windows, test=develop

* enable best_fit_allocator_test and test_math_op_patch_var_base, test=develop

Fix the condition of concat dimension judgment.

* update ResetHolder, test=develop

* add TensorShare for lite engine, test=develop

* tensor data changed from copying to sharing, test=develop

* supports xpu runtime, test=develop

* fix code styles, test=develop

* polish some error message in framework, test=develop

* fix unittest error, test=develop

* replace PADDLE_ENFORCE, test=develop

* polish details based review comment, test=develop

* add ci check for changing op-related api without core.ops, test=develop

* generate api_source_md5 file when build, test=develop

* add failed example, test=develop

* add failed example, test=develop

* handle exception, test=develop

* fix windows ci
test=develop

* fix ci error

* add reinforcement learning model test=develop

* align backward test=develop

* add gym in paddle_build.sh test=develop

* rm pip install in script test=develop

* refine paddle_build.sh test=develop

* fix sed error in macOS test=develop

* polish code test=develop

* fix scope problem

* refine code by reviewer comment

* polish install error hint msg, test=develop

* fix variable error, test=develop

* polish hint messgae again

* fix error msg report in ir/, about 5 files, test=develop

* fix error msg report in ir/, about 5 files, test=develop

* fix error msg report in ir/, about 5 files, test=develop

windows CI scripts for xly

refactor fleet api under paddle.fleet
update DistributedStrategy