* rm legacy layers part6

* rm non_static_mode

* modify non_static

* minor change

* rm loss

* rm in_legacy part8

* minor change

* Fix bug of reduce_sum op. When input.numel() > INT32_MAX, its result
is wrong.

* Remove climits.

* Clean Fluid APIs in python/paddle/fluid/layers/nn.py,
migrate spectral_norm and row_conv APIs, and remove ont_hot.
Including following files:
1. python/paddle/fluid/layers/nn.py
2. python/paddle/fluid/tests/unittests/collective/fleet/parallel_dygraph_transformer.py
3. python/paddle/fluid/tests/unittests/dist_transformer.py
4. python/paddle/fluid/tests/unittests/dygraph_to_static/transformer_dygraph_model.py
5. python/paddle/fluid/tests/unittests/ipu/test_one_hot_op_ipu.py
6. python/paddle/fluid/tests/unittests/test_imperative_auto_prune.py
7. python/paddle/fluid/tests/unittests/test_imperative_load_static_param.py
8. python/paddle/fluid/tests/unittests/test_layers.py
9. python/paddle/fluid/tests/unittests/test_one_hot_op.py
10. python/paddle/fluid/tests/unittests/test_row_conv_op.py
11. python/paddle/fluid/tests/unittests/test_runtime_and_compiletime_exception.py
12. python/paddle/fluid/tests/unittests/test_spectral_norm_op.py
13. python/paddle/static/nn/__init__.py
14. python/paddle/static/nn/common.py

* Polish code.

* Fix some bugs.

* Remove useless unittest.

* Fix some bug.

* Polish example code.

* Fix some bugs.

* Fix some bugs.

* 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

* solve conflicts of remove_lod_reset and latest develop version

* add lod_reset to the no_grad_set_white_list.py

* remove fluid.mul

* remove mul in __all__

* move conv2d

* code-style and build bug

* restore c++

* code-style

* rm fluid init conv2d

* remove nn.conv2d

* modify doc

[Clean Fluid API]Remove API: unsqueeze, use paddle.unsqueeze to replace paddle.fluid.layers.unsqueeze (#47936)

* Remove API: unsqueeze
	Replace the funcation call.
	Use paddle.unsqueeze to replace paddle.fluid.layers.unsqueeze

* Remove API: unsqueeze
	remove unsqueeze which is not used in Paddle 2.0

* Remove API: unsqueeze
	fix the bug by adding 'import paddle' to file
tests/unittests/test_rnn_cell_api.py

* Modify the call of unsqueeze from old style to new style

* fix the call arguments of unsqueeze

* replace unqueeze with paddle.unsqueeze

* fix the error in PR-CI-Static-Check, name 'paddle' is not defined

* fix the error in static in unsqueeze

* remove dropout

* remove linear_chain_crf and crf_decoding

* 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 pool2d

[Fluid Clean] remove unfold, deformable_roi_pooling, shard_index, hard_swish, mish, uniform_random, unbind (#48451)

* modify slice infershape

* code style

* modify slice_unittest

* temp fix

* batch_norm api move

* code_style

* codestyle

* ci_static

* add __init__

* reset other change

* revert .cc

* add import batchnorm

* conflict and revert

* fix bug

* fix third conflict one day

* fix conflict

* fix conflict bug

* fix conflict bug

* modify api

* code_style

* modify doc

* add lost doc stable

* fix conflict bug

* ci lack of gpu

* 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 fluild resize_trilinear

* clean fluild resize_bilinear

* clean fluild resize_nearest

* clean fluid image_resize

* fix test_trt_nearest_interp_op.py

* fix yolov3.py

* fix yolov3.py

* Clean fliud hash

* clean fluid grid_sampler

* clean log_loss

* Move bilinear_tensor_product from fluid to static

* Fix unitests when remove log_loss

* Fix bug when move bilinear_tensor_product

* fix test_fleet_nocvm_1.py

* Add bilinear_tensor_product into all list

* Fix code style

* Fix comments in bilinear_tensor_product

* Fix comments in bilinear_tensor_product

* Fix comments

[Fluid Clean] remove nn.topk, nn.ctc_greedy_decoder, nn.im2sequence, nn.multiplex, nn.smooth_l1 (#48289)

* move softmax to paddle2.0

* fix some bugs

* resolve conflict

* remove some code

* modify code style

* fix bugs

* fix code

* fix move code

* fix some bugs

* fix code

* fix some code

* modify the header file

* fix bugs

* fix some examples

* fix mish example

* fix code

[fluid remove]: remove paddle.fluid.layers.nn.temporal_shift and paddle.fluid.layers.sigmoid_focal_loss (#48553)

* remove paddle.fluid.layers.nn.temporal_shift

* code check

* rm unittest

* remove paddle.fluid.layers.sigmoid_focal_loss

* replace pad with paddle.nn.functional.pad and fix call arguments

* solve the ImportError in PR-CI-Mac-Python3, which is called "cannot
import name 'assign' from 'paddle.fluid.layers'"

* fix the CI error of remove_pad by remove import paddle.nn.functional as
F

* fix the ImportError of remove_pad

* fix functional call of pad

* replace log with paddle.log

* replace log with paddle.nn.functional.log

* fix the code style of remove_log

* fix the ImportError of log

* fix the error of modification of the dist_transformer.py

* fix error of Static-Check

* remove pool3d