* move fc from fluid to paddle2.0

* fix unit test

* fix some examples

* fix some examples

* remove paddle.fluid.layers.layer_norm

* templatedoc import from paddle.fluid.layers.layer_function_generator

* del import of fluid.layers.layer_norm in __init__.py

* add import of ..common.layer_norm in __init__.py

* fix bug in UT

* fix doc

* remove dropout

* add inner function _elementwise_op_with_axis

* fix transformer_model

* polish API code

* remove elementwise_div/mul api

* delete API in __all__

* delete elementwise_mul completely

* polish elementwise_mul call

* polish internal api

* resolve conflict, fix rnn.py

* use non-inplace call

* delete elementwise_mul api test

* delete elementwise_mul api test

* clean elementwise_add/sub

* restore _elementwise_op_in_dygraph in nn.py

* remove layers.matmul in nets.py

* remove layers.matmul in rnn_impl/test_quantization_pass/auto_parallel_gpt_model/test_auto_parallel_completion_gpt

* remove layers.matmul in other files

* fix

* fix

* remove layers.matmul itself

* remove ref in CMakeLists.txt and tools directory

* remove matmul in fluid.layers.nn.py

* remove matmul in fluid.dygraph.rnn.py && resotre test_matmul_op.py

* replace matmul in fluid.dygraph.rnn.py && clean api_test in test_matmul_op.py

* fix error && restore empty test_auto_search_dist_matmul_op.py

* fix check in test_auto_parallel_partitioner.py

* fix test_dist_matmul && test_flags_mkldnn_ops_on_off

* fix test_fused_attention_op_xpu.py && test_matmul_op_xpu.py

* remove test_auto_search_dist_matmul_op.py

* remove layers.matmul in auto_parallel_gpt_model.py && fix doc in fluid/io.py

* fix for matmul_grad

* fix codestyle

* fix codestyle

* resolve conflicts error

* restore unit test file but not compiled it for later remove

* fix codestyle

* fix wrong unittest skip

* fix unittest delete

* fix scale cost

* fix scale cost

* resolve conflicts error

* resolve conflicts error
Co-authored-by: Njakpiase <jakpia21@gmail.com>

* clean elem_arithmetic part6 unittest

* delete op_name_conflict unittest

* restore test_op_name_conflict

* fix codestyle test_op_function_generator

* remove fluid.reduce_sum

* remove fluid.reduce_sum

* modify axis and import paddle

* modify keepdim and out_name

* modift unittest

* modift unittest

* modify CI_static and loss.py

* modify test_mse_loss

* modify static ci

* modify static ci datatype

* add import paddle in test

* fix conflict

* fix conflict

* modify ci

* modify ci

* fix_conflict

* fix bug

* code_style

* remove transpose

* codestyle check

* modify CI_STATIC

* modify CI_STATIC

* modify enable static()

* remove unused import

* fix conflict about stack

* fix conflict about stack

* fix conflict about stack

* endless conflict

* remove reshape in nn.py under fluid

* remove reshape reference

* fix test case

* fix test case in distribution.uniform

* remove fluid reshape reference

* remove apis in fluid.ops

* fix test_activation_nn_grad

* fix circle import error

* fix ops

* fix cos

* fix divide not inplace

* remove lazy-import part

* update config

* re-blacken python code

* temporarily disable date and diff_py_file

* skip a format

* [CodeStyle] remove all future import

* revert test_error.py

* restore future import in example code

* use yapf to format all python file

* yapf exclude two unittests file for they rely on writing and reading file, and format will break them

* disable diff_py_file because too many diff files cause command following failed

* fix spelling errors; test=develop

* Update API.spec

update md5

* Update API.spec

* change the order of api;test=develop

* add GraphNum

test=develop

* add graph number check in parallelExecutor

test=develop

* fix transformer_model bug

test=develop

* fix graph num

* hide misc APIs

* update

* fix transformer test

* update API.spec