Unmaintained, and manual `run` commands are more readable anyhow.

This avoids compiling a binary for each separate test. Makes it much
easier to point a debugger at psm test cases too.

This really has a couple benefits – first, is that we have an
opportunity to simplify the code in some instances. But most
importantly, we no longer need to deal with external assemblers and
different syntax for each.

Eventually we might even be able to utilize them macros to reduce
duplication too!