Merge pull request !4039 from wangzhe/master

Merge pull request !4093 from sunsuodong/relu6_int8

Merge pull request !4077 from wangchangkai/master

Merge pull request !3951 from songhonglei413/test

Merge pull request !4079 from yankai10/new_merge

Merge pull request !4006 from Simson/enhancement-API

Merge pull request !4062 from yangruoqi713/fix_bug

Merge pull request !4010 from changzherui/mod_ckpt_param

Merge pull request !4072 from hewei/fixbug_tensor_equal

Merge pull request !4050 from fangzehua/unsortedgrad

Merge pull request !4080 from andy_wangrui/master

Merge pull request !4056 from liubuyu/bug_fix

Merge pull request !4026 from 34bunny/CMake-debug-mode-fix

Merge pull request !3831 from danishnxt/GPU_One

Merge pull request !3961 from lixian/master

Merge pull request !4040 from sunsuodong/strided_slice_int8

Merge pull request !4071 from zhanyuan/tmp

Merge pull request !4070 from yeyunpeng2020/master_profile

Merge pull request !4047 from zhangbuxue/add_attr_dtype_and_shape_and_interface_asnumpy_for_tensor

Merge pull request !4060 from fary86/fix_while_concat_specialize_error

1. Check if data_ is null before compare it;
2. Always allocate an array for data_ even if size is zero.

Merge pull request !3967 from vlne-v1/I1Q23G-pynative-parameter-not-init

Merge pull request !3786 from baihuawei/multinomial

Merge pull request !3886 from wangminggui/master

Merge pull request !4017 from wangchangkai/master

Merge pull request !3973 from zhengjun10/master