einsum support complex and add unittest.

* refine dist_grad kernel

* fix cpu kernel bug

* refine dist kernel, reuse norm

* follow comments

* feat(): dynamic_to_static support for ipu.

* fix(): format fix.

* fix format

* fix cpplint error

* use phi::errors

* fix format

* fix format

* fix(): add api to restore patched function.

* fix(): identity_loss uses cpu place as expected kernel type.

* doc(): add IPU dy2static related docs.

* fix(): combine test cases.

* fix format

* fix comment

* fix format

* apply comment

* fix compiling

* fix(): align docs.

* fix(): fix identity_loss function docs.

* fix(): adjust mean and sum in identity_loss.

* fix(): minor docs.

* move API to paddle.incubate.identity_loss

* fix UT
Co-authored-by: Nzhaorui chen <zhaoruic@graphcore.ai>

* [Sparse] add SparseCsrTensor fused_attention kernel and API

* fix comment

* fix init()

* delete test_device_context

* replace CPUDeviceContext with CPUContext

* fix test_scalar

* remove dot_op.cc

* fix compile

* unify cpu context

* fix init()

* delete test_device_context

* fix test_scalar

* 2nd part of transpose update

* add switch_auto_tune option.

* add some changes according to Ci

* refine the structure of auto_tune_base.

* merge develop changes

* reset the switch_set_range and change unittest of transpose auto-tune

* change the kernel auto-tune logits

* move standard apis to api.yaml

* revert erfinv

* delete dot_op.h

* fix dot

* rerun ci

* add relu6 kernel and yaml

* format files

* format code and fix bug

* fix build failed

* move cross form legacy_api.yaml to api.yaml

* move diagonal to api.yaml

* [Sparse]add SparseTensor mv kernel(csr*dense_vec->dence_vec, coo*dense_vec->dense_vec)

* fix CI

* move apis from legacy_api.yaml to api.yaml

* remove comment

* revert argsort

* fix merge conflict

* perfect copy

* deal with conflict

* deal with conflict

* fix compile bugs

* fix unittest bugs

* change code format

* deal with conflict

* modify code by review

* fix ce bugs

* fix ce bugs

* add lo

* perfect code format

* deal with conflicts

* Remove unnecessary including for pstring.h

* Fix typos

* cpplint fix 3

* cpplint fix 3

* cpplint fix 3

* cpplint fix 3

resort .cu headers, set clang-format not sort include block and consider .cu as main source file (#43633)

* add new API/OP(csr->csr) of SparseTensor softmax

* fix comment