Macros are broken

[japanoise]

What happened: Double free or corruption on M-| + macro

On executing the macro:

Shell command on region: double free or corruption (top),
                                                        zsh: IOT instruction  emsys

   ~/src/emsys main 1m 6s
>       

How to reproduce: Use repro steps from #12 but use M-1 to make the pipe command send its input to the buffer

Expected: Either fails gracefully or goes smoothly through #12 good-case.

[japanoise]

I think macros may just be straight up broken. Playing a simple macro (e.g. C-x ( q u x C-x e) makes emsys hang.

[japanoise]

I suspect it may be that the "start recording macro" and/or "end recording macro" keys might be ending up in the macro buffer. We did a lot of big refactors and the protections against this happening may have crapped out.