This is required for the new core_log and rtio_log functions, which take
a generic type as its parameter. However, in ARTIQ builtins are
initialized using one unifier and then actually used by another unifier.
lateinit_builtins workaround this issue by deferring the initialization
of functions requiring type variables until the actual unifier is ready.
- Add helptext for check_demos.sh
- Add back support for using debug NAC3 for running tests
- Output error message when argument is not recognized
- Fixed last non-demo script argument being ignored
- Add back SSE2 requirement to NAC3 (required for mandelbrot)
