* copy api from paddle to paddle.fluid, test=develop

* fix optest, test=develop

* add decorator, test=develop

* add fake_interface_only, test=develop

* remove some dygraph_not_support, test=develop

* change dygraph to imperative, test=develop

* cherrypick: add kron op (#24105)
* add kron op and fluid.layers.kron
* add paddle.complex.kron

* update index sample

* API/OP (affine_channel, group_norm, layer_norm, random_crop, unpool, log_loss) error message enhancement test=develop

* adapt old version pretrain model load, test=develop

* fix infer error & multiple input error, test=develop

* Error message enhancement of 6 op, test=release/2.0
* refine huber loss unittests, test=release/2.0

* fix test_multiprocess_dataloader_base timeout. test=develop.
test=release/2.0

test=release/2.0

* Init complex number neural network, test=release/2.0

* Improve doc writing

* Fix elementwise add & sub

* Fix elementwise mul act

* a) add ut for complex variable; b) remove arg act in elementwise_ops

* Add trainable_statistics in attr for batch_norm
* Unifying behavior of dynamic graph and static graph

* add nll_loss op test=develop

* cherry-pick: fix converage ci (#23738)

test=release/2.0-beta

* modity ut
test=release/2.0-beta

test=release/2.0-beta, cherry-pick PR #23809: add 'seed' arguemnt of randint API

* fix tribilinear unitest, test=release/2.0

* add random seed,test=release/2.0

* Chery_pick:[Eernie TRT]: add slice op and add emb eltwise layernorm fp16 support (#23723)

* refine ernie trt dynamic shape support
1. add slice op converter
2. add emb eltwise layernorm fp16 support
test=develop

* fix dynamic shape test ut
test=develop

* fix comments.
test=develop

* fix comments
test=develop

* cherry-pick [BUG]: Head number can only be > 1 on multihead op (#23974)

* support the head number == 1
test=develop

* fix slice op error.
test=develop

* cherry-pick :disable trt test, test=develop (#23984)

test=release/2.0-beta

* add diag_embed op (#23385)

* add diag_embed op, test=release/2.0-beta

* solved a conflict, test=release/2.0-beta

* lod_rank_table error message enhance. test=develop

* Add `nn.interpolate ` (#23434)

* add bmm and arange op test=develop

* add bmm and arange op test=develop

* update bce docs,test=release/2.0

* update docs, test=release/2.0

* cherry-pick OP Normal, Uniform, Xavier Initializer, smooth_l1, mean_iou error message enhancement (#23751)  test=release/2.0

chery-pick from the pr#23978

* enhance pad.* error message, test=develop

* error message enhancement create_parameter create_global_var, test=develop

* use six.PY2 to use long, test=develop

* fix input dtype for create_parameter, test=develop

add manual_seed op into paddle.framework.random

* Add `paddle.nn.loss.MSELoss`

test=develop

* Move to `nn/layer/loss.py`

test=develop

* Fix dygraph

test=develop

* Add test

test=develop

* Increase numel in test

test=develop

* Add test for input with different dimensions

test=develop

optimize compare and logical ops error info, add test case for this ops， add some test case for those ops

cherry-pick #23645