* Fix paddle.pow() bugs

* Add unittest cases

* Fix ut cases

* Add ut cases on multiple devices

* Create elementwise_heaviside_op.cc

* add ElementwiseHeavisideFunctor

* Create test_elementwise_heaviside_op.py

* 增加heaviside的python接口

* add heaviside in white list

* 增加heaviside的签名

* 增加heaviside的核函数

* 增加heaviside梯度的核函数

* 增加heaviside梯度的注册

* 调整代码格式

* Update elementwise_sig.cc

* add heaviside in __all__

* Update heaviside docs

* Update math.py

* Update math.py

* Update math.py

* regist elementwise_xxx

Revert "Revert "[Phi] Move elementwise_floordiv and elementwise_pow to phi (#40993)" (#41065)" (#41110)

This reverts commit 3a6f1135.

This reverts commit b532315d.

* mv floordiv to phi

* mv elementwise_pow to phi

* fix as review

[phi] Transfer lgamma, kldiv_loss, isclose, cumprod kernels into phi and pass the tests of these four kernels (#39770)

* tranfer and pass the lgamma unittest

* merge and pass the test

* transfer kldiv_loss and kldiv_loss_grad; pass the unitest

* trafer the isclose and cumprod kernel

* change PT_REGISTER -> PD_REGISTER

* fix by code review

* fix by code review

* fix

* remove enforce include dependence from scalar

* fix

* fix by code review

* fix by code review

* move elementwise_div grad

* change mutable_data to alloc

* fix compile bugs

* rename pten dir to phi

* rename namespace to phi

* rename infrt pten dir to phi

* resolve conflict

* rename pten to phi in cmake

* revert all infrt change

* change needed files

* fix infrt failed

* fix inference failed

* transfer: string tinyformat errors and part of enforce into pten

* remove comment

* fix by code review

* assert is not compile in -DNDEBUG

* add string as dependences of paddle_inference

* Migrate Dim and DDim from paddle::framework into pten namespace

* fix paddle::framework::Array

* fix framework::Array

* Migrate bfloat16/float16/complex from platform into pten::common

* fix typo

* fix code style

* change 'math' to 'math_kernel'

* fix compile bugs

* merge develop

* fix compile bugs

* move cpu_impl of elementwise kernel to new directory