Jeff Epler efffb62b36 truncate boot_out.txt if it's long
Now this boot.py:
```py
for i in range(1000):
    print(i)
```
creates a 512-byte boot_out.txt that ends
```
88
89
...
```
2021-11-02 18:23:42 -05:00
..
2021-11-02 18:23:42 -05:00
2021-11-01 23:05:34 -05:00