* [XPU] add numel op

* [XPU] update numel/size op registration

* move python/paddle/fluid/tests/unittests/xpu to test/xpu

* update CMakeLists.txt

* remove xpu in fluid/tests/unittests/

* add path to op_test_xpu

* fix incorrect path

* update test script

* fix test_adadelta_op_xpu error

* [XPU] add increment op.

* fix ci

* del array_write & array_read

* fix import err

* fix import err

* fix example codes

* update config

* re-blacken python code

* temporarily disable date and diff_py_file

* skip a format

* [CodeStyle] remove all future import

* revert test_error.py

* restore future import in example code

* change fluid.mean to paddle.mean

* reverse some old code examples

* ignore some failed test for KL2
*test=kunlun

* minor
*test=kunlun

* minor
*test=kunlun

* fix uint8 check in assign

* fix assign unittests

* fix xpu test_assign

paddle.to_tensor will be translated to paddle.assign in Dy2stat, however paddle.assign doesn't support int, float, bool. This PR added the supports.

* addd

* add cast_op_xpu, test=kunlun

* fix bug for cast_op_xpu,test=kunlun

* add concat_op_xpu, test=kunlun

* slove conflicts, test=kunlun

* fix bug,test=kunlun

* add assign_op_xpu, test=kunlun

* fix bug,test=kunlun

* test=kunlun;test=develop

* fix concat bug,test=kunlun

* fix check_dygraph set in test_concat_op_xpu.py,test=kunlun

* fix error message,test=kunlun
Co-authored-by: Nmapingshuo <mps2012@yeah.net>

* Add the support of bool list for assign value, test=develop
* Fix the assign op test case for bool dtype, test=develop

As the title.

* register fp16 for assign op, test=develop

* add op test for fp16, test=develop

* fix python API tests that do not need to inherit OpTest, test=develop

* fix fp16 cases that will only be enabled in GPU mode, test=develop

* remove TestSoftmaxFP16Op from test cases of softmax_mkldnn_op, test=develop

* fix tests so that the cases are only created in GPU mode, test=develop

* Fix the assign data check. test=develop

* Fix test_assign_op.py. test=develop

* Fix the error message of assign op
test=develop

* Refine input type checking for assign op
test=develop

* Refine unittest of assign op
test=develop

Currently, our tests run with 2 GPUs, the init time is absurdly long:
about 4s for each process.  Currently, we run each OP test on
different processes. This PR:

1. create cmake function py_test_modules which will generate the
Makefile that runs a list of Python unittest module in a single Python
process.

2. move all "python unittest compatible" (e.g., used the unittest
package, not just a regular python file). from fluid/tests to
fluid/tests/unittests.

3. cmake now will run all OP tests in fluid/tests/unittests in a
single process, except the time-consuming tests, they are separated
into different processes to utilize parallelism. Please make sure to
use the unittest package if you put the python test file in
fluid/tests/unittests

4. remove all exit(0) from fluid/tests/unittests/*.py, exit(0) is used
to disable unittest, we can not do it when running all tests in a
single process since it will terminate the process without running the
other tests. Instead, the test is disabled in
fluid/tests/unittests/CMakeLists.txt. FIXME is added for each disabled
item. Please disable the unittest from
fluid/tests/unittests/CMakeLists.txt, instead of adding exit(0) to the
Python file, for all Python file in fluid/tests/unittests/.

5. add an option WITH_FAST_BUNDLE_TEST. When OFF, will run the unit
tests in separate process so that they can be tested individually.

* "fix decode bug"

* "follow commnet"

* "fix error"

* "fix hook bug"

* fix based comment

* fix copyright

* fix based on comment

* add copyright hook

* add copyright hook

* refine copyright hook

* "test copyright hook"

* fix check style

* fix ci

* init commit

* change some dir name

* Assign Operator.

Out=X, when type in [LoDTensor/SelectedRows/LoDTensorArray]

* Follow comments