Small refactor of shape guards to allow for 1:1 code_parts (#93894)
By moving guard string assembly into dynamo's default behavior and letting code_parts do the work, we can have much better shape guard failures.
Before this fix, the guard failure in the test would look like:
```
'x.size()[1] == x.size()[0] and x.stride()[0] == x.[264 chars]!= 1' != 'x.size()[0] < 3'
- x.size()[1] == x.size()[0] and x.stride()[0] == x.size()[0] and x.stride()[1] == 1 and x.storage_offset() == 0 and y.size()[0] == x.size()[0] and y.size()[1] == x.size()[0] and y.stride()[0] == x.size()[0] and y.stride()[1] == 1 and y.storage_offset() == 0 and x.size()[0] < 3 and x.size()[0] != 0 and x.size()[0] != 1
+ x.size()[0] < 3
```
now it is
```
"x.size()[0] < 3"
```
Pull Request resolved: https://github.com/pytorch/pytorch/pull/93894
Approved by: https://github.com/ezyang
