* add stat tool

* add roll and roll_grad kernels and strided_slice and strided_slice_grad kernels, test=kunlun

* add silu, unfold and their grads,test=kunlun

* decouple im2col from fluid

* move im2col to phi

* fix build error

* delete redundant comment

* fix maybe-uninitialized warning

* fix compile

* fix xpu compile

* fix npu compile

* fix infer compile

* fix compile

* fix compile

* [Phi] Migrate unfold_op into phi

* fix im2col CPUContext template instantial

* fix unfold_op.h header include problem

* fix unittest

* fix PT->PD