* #1 migrate dist-related type()-> dtype()

* move datatype function from pten -> fluid/framework

* change type() in imperative into convert(dtype())

* modify xx_tensor->type into xx_tensor->dtype

* change the set_type interface and the caller

* modify xx_tensor.type into xx_tensor.dtype

* fix mutable_data(place, dtype())

* change caller of mutable_data in pten and distributed

* change the caller of mutable_data in fluid/framework

* change the caller of mutable_data in imperative directory

* mutable_data: inference

* update the call of mutable_data

* transfer MakePenScalarArray MakePtenScalar ResetHolderWithType

* pass the compile. the next step is remove VarType in Pten

* fix all and remove VarType from pten. success in linux. Next task is other platform

* fix conflict with develop

* fix compiled error

* Fix reset conversion

* fix conflict

* fix compiled problem

* fix typo

* Fix << in tensor_utils.cc

* fix type->dtype

* fix unittest

* fix tensor init constructor

* fix DataTypeSize for BFloat16

* fix code style

* fix npu compiled error

* fix npu

* compile npu sucessfully

* fix conflict

* fix conflict
Co-authored-by: Nxiongkun <xiongkun03@baidu.com>

* move operators/math/math_function_* to pten/kernels/func
* namespace from `paddle::operators::math` to `pten::funcs`

* Add paddle.linalg.eig op

* remove comments

* remove comments

* extend batch_size to the origin

* add real times complex functor & destroy the backward complex output bug

* terminate output diff when input real tensors

* correct tiny doc errors

* move functions from eig_helper to svd_helper and remove eig_helper

* remove tensor.Resize

* remove no longer used code

* use existing lapack functions

* reply review comments 21/27

* remove .cu as this op is only executed on CPU

* remove const_cast & add const in argument list for read-only references

* fix sample code error in CI

* remove template typename Tbase and more

* remove eig exposure in paddle.*

* add 'name=None' in eig python implementation

* handle the unittest

* try to solve the unittest

* solve CI coverage

* remove no longer used code

* polish API doc and more

* reply review comments

* polish unittest, commit plan B

* polish unittest