* zero-tensor

* remove unused

* zero_dim_xpu

* relocate

* add value test

* fix syntax

* [D2SCinn]Add test_cinn unittest and param_grad into skip_gc_vars

* remove print

* acquire custom_deivce stream

* regulate file name and unittest

* flatten op support 0D-tensor

* add test in zero dim py

* fix shape should be list

* short code for ci-coverage

* add backward test

* simple code for ci coverage

* add axis check

* add 0D-tensor test in test_flatten_contiguous_range_op.py

* add axis error test for Coverage CI

* add more test for CI-Coverage

* add more test for CI-Coverage

* fix: fix hidden virtual funcs

* fix: add default impl

* [Auto Parallel] Rename methods of ProcessMesh

* [Auto Parallel] Impl the python process_mesh by the c++ one

* [Auto Parallel] Add some minor modifications

* [Auto Parallel] Rename some methods

* [Auto Parallel] Remove unnecessary codes

* [Auto Parallel] Add back some removed files

* [Auto Parallel] Fix bugs

* [Auto Parallel] Fix a bug

* Update process_mesh.cc

* [Auto Parallel] Merge dist attrs of Python into C++

* [Auto Parallel] Add back deleted importing

* [Auto Parallel] Add back removed unittest

* [Auto Parallel] Remove type qualifiers of return types

* [Auto Parallel] Fix some bugs

* [Auto Parallel] Fix a bug of the quant pass

* [Auto Parallel] Fix the code style

sequence_mask fix: when the input length is an empty tensor, the kernel tries to dereference illegal sentinel iterator (#49525)

* support 0D for paddle.sort/argsort

* support 0D tensor for paddle.sort/argsort in xpu

* fix bug

* fix grad and add value assertion

* generate the static graph code of ops

* modify the isclose comment

* modify the clip comment in nn.py

* reset nn.py

* update nearest_interp, expand_v2, cast for stable diffusion

* update nearest_interp, expand_v2, cast for stable diffusion

* correct shape rank

* Update expand_v2_op.cc

* add pool flops

* add annotations and tests

* CINN add fetch op for skip gc vars

* perfect test annotation

* break if not is_only_used_internal

* move skip_gc_var_names get out of for loop

* rm op_function_generator

* rm op_func_generator.h

* rm op_function

* modify cmake

* rm op_function.h

* rm check for op_function_generator.cc

* reset imperative

* rm python part

* fix imperative

* lint

* lint

* modify legacy_c

* review

* modify

* modify legacy

* rm gen op_functions code

* reset framework

* rm core.ops for test

* core.ops->core.eager.ops.legacy

* not raiseError for xpu

* refactor: use base class

* fix: incorrect deps

* fix: add missing header

* refactor: update class structures

* fix: bkcl typo

* fix: remove redundant def

* [Eager] optimize same python api logic

* optimize full api

* optimize logic

* optimize logic

* delivery skip_gc_vars from the main graph to each subgraph compiled by CINN

* rearrange format and annotation

* fix lacking namespace

* fix segmentation fault cinn subgraph doesn't own kSkipGcVarNames

* deliver all skip_gc_vars of main graph

* add vlog for skip_gc_vars

Add 0d Tensor Test Cases for cond, case, switch_case. Since the 3 APIs are control flow APIs, their support for 0d tensor relies on the underneath APIs. This PR just added test cases to prove that the 3 APIs have already handled 0d tensor well.