* [x] basic_free_stack https://github.com/lcompilers/lpython/pull/2268 * [x] simplify the pass, currently it is about 2K lines, I think a lot of repetitions can be refactored. https://github.com/lcompilers/lpython/pull/2263 * [x] https://github.com/lcompilers/lpython/issues/1907 * [ ] examples don't work with `--fast`
--fast