A lot of work, on various parts of the compiler, mostly adding simd type/structure information to places it needs to be

Mostly work on connecting the basis library and the runtime system, making sure type/function/structure names match up etc.

Currently I'm working on elaborate, because currently the compiler fails saying that the simd structures in c-types.sml are undefined

I also did a bit of work on writing some basic tests for the simd stuff, just to make sure the simple stuff works

I think I've almost got things working, I just need to do a little more work and I feel like things will start to `click`, so to speak