* support pure bfloat16

* support bf16 linear

* update PR to pass CI

* tiny fix where_grad_kernel.cu

* add bfloat16 to selu_grad to pass CI

* fix selu grad compilation error

* remov merged_adam_op to phi

* refine code

* 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

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

* refactor the optional tensor

* remove optiona<MetaTensor> in InferMeta

* fix bug

* fix optional<vector<Tensor>>

* fix bug

* fix rmsprop

* fix amp of eager_gen

* polish code

* fix deleted code

* fix merge conflict

* polish code

* remove is_nullopt_

* fix merge conflict

* fix merge conflict

* [Phi]Fix beta1_pow/beta2_pow/skip_update data transform problem in adam/adamw

* fix xpu unittest failed

* [Phi] Migrate Adam and Adamw into Phi

* fix compile error and unittest ok

* fix compile error and unittest ok

* fix undefined reference to fLI::FLAGS

* test depend on operator

* fix cmake

* fix xpu compile

* fix infrt

* fix amp_type_traits

* fix amp_type_traits

* modify according reviewer

* modify according reviewer

* fix dtype float16

* fix typo

* fix Cmake

* fix code style