- 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 !1928 from yoonlee666/deletereshape

This reverts commit 705c71a257.

* add infer_value for common math ops
* convert constant bool tensor to bool value

* do not infer value when encounter 0 as division

for while condition, do not unrool if condition is a tensor

This reverts commit 3db8cfa54f.

This reverts commit ea6958c50a.

Signed-off-by: leonwanghui <leon.wanghui@huawei.com>