`lessThan` ran into infinite recursion.

```
$ git fetch origin wjy/recurse
$ git checkout wjy/recurse
$ _bn && NVFUSER_DISABLE=parallel_compile python repro.py
```

`NVFUSER_DISABLE=parallel_compile` is there to display the call stack better. 

To make debugging easier, I limited recursion of `lessEqual` to 100 levels. The reproducer is still valid but slower with that check removed. 