- It provides a unified style to express graph and kernel for user.
- It provides a unified IR to represent graph and kernel for developer.
- It breaks the boundary between graph and kernel.
- It provides more opportunities to do compile optimization.

Merge pull request !1628 from 刘崇鸣/model_zoo_mass

Merge pull request !2260 from liyanliu96/liyan

Merge pull request !2388 from VectorSL/bert-eval

Merge pull request !2387 from wukesong/cpu-lenet-sink-true

Merge pull request !2382 from chenzhongming/abc

Merge pull request !2370 from changzherui/mod_alexnet

Merge pull request !2367 from yoonlee666/edit-example

Merge pull request !2341 from wukesong/add_src_dir

Merge pull request !2368 from chenzhongming/abc

Merge pull request !1663 from wukesong/change_network_path

remove graphengine changes

concat op

Truncate Pair

concat_op

remove graph engine changes

ToNumberOp implementation almost done

ToNumberOp complete

ci fix

ci fix

ci fix

ci fix

ci fix

ci fix

ci fix

ci fix

ci fix

ci fix

merge conflicts

Merge pull request !2202 from yuchaojie/transformer

Merge pull request !2279 from zyli2020/add_model_script_of_wide_deep_for_gpu

Merge pull request !2217 from chengxb7532/cxb_st

Merge pull request !2201 from chenweifeng/gpu_bert

Merge pull request !2144 from caojian05/ms_master_dev

Merge pull request !2119 from zhangdengcheng/master

Merge pull request !2061 from shibeiji/master

Merge pull request !2009 from chentingting/gcn_modelzoo

Merge pull request !1956 from z00378171/master

Merge pull request !1672 from yihuaijie/dev

Merge pull request !1997 from chengxb7532/cxb_st