The amount of almost-identical duplicate Makefile goop to support running the tests against the various different stages of the compiler finally hit a point where I decided committing some hideous acts of GNUMakefile macroing was the lesser evil...
https://github.com/swetland/spl/blob/4057d1ea99906bdbb233349b44e3f4de889fc078/Makefile#L116-L166
edit: annoyingly, after posting this I found a typo in a comment.
