Add examples for error message writing specification - PreconditionNotMet, Unimplemented, Unavailable (#21137)

* add examples for error spec, test=develop

* change ENFORCE to ENFORCE_**, test=develop

* fix warning info
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* fix bug of all_reduce_deps_pass
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* Open fuse all reduce op
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* Add Fuse optimization op log

* Add log in fuse_optimizer op pass and fuse all_reduce op pass

* replace with boost::optional<bool>
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* Polish code
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* fix code coverage
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* fix vlog level and fuse option type
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* Enable fused_all_reduce_op_handle support GPU and CPU Gradients

* enable ngraph throught build_strategy test=develop

* add unittest test=develop

* put use_ngraph unconditional test=develop

* remove paddle_enforce test=develop

* remove paddle_enforce test=develop

* fix copyright test=develop

* limit for ngraph only test=develop

* Disable fuse optimization
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* remove legacy memory optimization codes, test=develop

* follow huihuang's comments,test=develop

* follow luotao's comments, test=develop

* open fuse optimization ops
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* first version memory optimize pass, test=develop

* remove move_tensor_sharing_pass, test=develop

* refine code comments, add unittests, test=develop

* turn off memory_optimize by default, test=develop

* follow huihuang's comments, test=develop

* follow chengduoZH's comments, test=develop

* fix grammar error, add const qualifier, fix pass_test exception message, test=develop

* follow chengduoZH's comments 2nd, test=develop

* support sparse gradients
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* feature/buffer_shared_inplace, test=develop

* refine code, test=develop

* fix elementwise_add op cpu inplace and sum inplace bug, test=develop

* add unittest and debug log, test=develop

* fix parallel_executor scope bug, polish code, test=develop

* fix sum op, activation op, single_in_place_inference bug, test=develop

* remove kLocalExecScopeName, test=develop

* fix unittest,test=develop

* fix out_var first version bug, test=develop

* follow comments,test=develop

test=develop

* make parallel_executor support FLAGS_use_mkldnn

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* add warning when set mkldnn_enabled_op_types_ in non-mkldnn env

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* move pass to ir

* polish code
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* fix dependency
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* add use_cuda to inplace pass,test=develop

* add test softmax_with_xe_inplace test,test=develop

* Add fuse momenutum ops

* speedup gc and inplace softmax_with_cross_entropy_grad
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* refine models gpu mem
Merge skip vars and warning messages of mem opt
remove relu mem opt
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* follow comments
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* fix bug of fuse optimize ops

* Add an option to enable the cache of expected kernel in train phase.
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* Change the default value of cache_expected_kernel to true.

* Try to enable the runtime_context_cache pass in train phase.

* Put the append of runtime_context_cache pass ahead of multi_dev passes.
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* fuse optimizer

* modify the interface of Pass::Allay
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* Polish code
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* Fix Travis CI
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* fix Pass::Apply interface
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* Fix Travis CI
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* refine parallelExecutor
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* Polish op_handle
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* Remove unnecessary op_handle
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* Fix Travis CI
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* Fix fetch bug
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* Remove WaitInputVarGenerated

* Fix OpHandleBase::Run
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* debug
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* use origin fetch_op_handle
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* Revert op_handle_base.cc
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* Polish code
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* Fix OpHandleBase::Run
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* code refine

* test CI and CE
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* fix OpHandle::Run
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* refine AllReduceOpHandle
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* Polish code
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* fuse all_reduce
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* add fuse_parameter_groups_size
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* Polish code
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* Fix travis-ci
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* Add SetGroupAccordingToLayers and SetGroupAccordingToGroupSize
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* Add SetGroupAccordingToMemorySize
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* fix multi_devices_graph
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* reset params_grads
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* Polish code
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* Support Sync Batch Norm.
* Note, do not enable it in one device.

Usage:

build_strategy = fluid.BuildStrategy()
build_strategy.sync_batch_norm = True
binary = fluid.compiler.CompiledProgram(tp).with_data_parallel(
        loss_name=loss_mean.name,
        build_strategy=build_strategy)

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