GH-98831: Add `macro` and `op` and their implementation to DSL by gvanrossum · Pull Request #99495 · python/cpython

(But this needs to be cleaned up for maintainability.)

Also:
- Add helpers for indent management;
- Reformat with black.

This was popping the common items off the stack.

I thought I got them all...

Co-authored-by: Brandt Bucher <brandtbucher@gmail.com>

Co-authored-by: Brandt Bucher <brandtbucher@gmail.com>

This simplifies a few lines in the code generator.