Create use q3vm as possible backend

[mingodad]

I recently have been looking at https://github.com/jnz/q3vm and it seems to be a possible backend for neat and with it neat can be interpreted for fast development/iteration.

[mingodad]

Just out of curiosity I replaced all ".+"[0] and it does build fine see attached the diff.
dad-char.diff.zip

[FeepingCreature]

Yeah I added char support recently, they're all replaced on current master. It needs to build with the bootstrap compiler.

[FeepingCreature]

Having an interpreted backend is... complicated. I would like to be ABI compatible with compiled C, if possible, so I can easily call passed classes in macros. That said, unless it's very performant it wouldn't give any development time improvement, because the interpreted code would run slower than the compiler needs to build itself. It'd be a net loss, in other words.