On Windows, SDL headers define `main` to `SDL_main` in addition to doing
it through `pkg-config`. The countering `#undef` must occur after the
headers are included. Commit 2a82207 changed the `#undef` to occur too
early. Linux works fine, but Windows broke.
Move the `#undef` back down. Switch to named format parameters to make
it easier to maintain.
Fixes: 2a82207e91 ("Add unit tests for valptridx parameter validation")
7d4c521382