[CodeStyle][F821] fix undefined variables due to missing imports, misspelled variable names (#47899)

* `hann` -> `_hann`

* `false` -> `False`

* a missing passed argument `reduce_all`

* some missing imports

* `device_type` -> `heter_device_type`

* `PKVClient` -> `KVClient`

* fix some typos and missing imports

* fixed cond state

* fixed cond state

* feat(ipu): add model_runtime backend support in IPU.

* fix(ipu_executor): fix error message format.

* fix(ipu_executor): fix format.

* fix(ipu_executor): fix format again.

* fix(ipu_executor): fix format again.

* fix(ipu_executor): fix format again.

* refine shape op in new_exe

* Revert "refine shape op in new_exe"

This reverts commit 0e0336ddc5eede3da019b348a0bcc0ef0f3be64e.

* refine shape op in new_exe

* refine shape expected_kernel_type

* add SelectedRows check for shape op

* refine code

phi::Alloc() complains about missing device_allocator_

* generate static graph code for some ops by yaml

* remove deleted files

* update cmake

* update cmake

* udpate cmake

* fix cpu build failed

* update

* rm "paddle/fluid/operators/eigen/eigen_function.h" in phi

* rm "paddle/fluid/operators/elementwise/elementwise_op_function.h" in phi

* Revert "rm "paddle/fluid/operators/elementwise/elementwise_op_function.h" in phi"

This reverts commit c4ba51225e3652f1d80925afba406612968f0ee9.

* migrate prelu

* remove cache

* review fixes

Get grads types from cpp for adam to speed up

* standard api

* fix sparse bugs

* fix xpu bugs, test=kunlun

* remove hard code for custom unittest

* open ci, test=kunlun

* deal with conflict

* remove fluid/framework/generator.h from phi

* fix PR-CI-Kunlun-KP-Build fail

* add recompute doc.

* add recompute doc.

* add recompute doc.

* update.

* update.

* rm fluid gpu_launch_config

* fix type

* add roformer pass&&plugin（novarlen）

[PHI Decoupling] remove "paddle/fluid/platform/float16.h" and "paddle/fluid/platform/for_range.h" in phi. (#47817)

* rm "paddle/fluid/platform/float16.h" in phi

* rm "paddle/fluid/platform/for_range.h" in phi

[PHI Decoupling] remove dependency on "paddle/fluid/platform/errors.h" and "paddle/fluid/platform/fast_divmod.h" in phi. (#47815)

* rm "paddle/fluid/platform/errors.h" in phi

* rm "paddle/fluid/platform/fast_divmod.h" in phi

* add c_concat pass for reshard

* add unittest

change cudnn error to cuda error if compiled cuda version is incompatible with installed cuda version (#47743)

* fix cudnn error

* fix

* fix

* fix

* XPU support eager mode

* add unittest for XPU eager mode

* minor bugfix

* minor bugfix, test=kunlun

* correct copyright info

* 1. remove unsed vars/funcs
2. ProcessGroupBKCL inherit from ProcessGroupStream

* bugfix for fp16 in eager mode multi-card, test=kunlun

* rebase & fix a few issues

* use new processgroup interface, test=kunlun

* fix compile issue, test=kunlun