* support 0-D output and 0-D as indice in __getitem__

* fix tests

* fix inference and UT

* add unittest for setitem

* fix xpu test

* fix xpu 0-d

* 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

* mv paddle/fluid/platform/device/xpu/tests 2 test/xpu/cpp

* add missing cmake