Cast: BigInt/Object Compatibility + New Block

[LilyMakesThings]

I noticed recently that because of the way I programmed it, Cast doesn't read types aside from string, number and boolean. This is fine for vanilla TurboWarp, but for extensions like BigInt and the potential new Object extension, that's a problem.

(I also accidentally closed this a few weeks ago and didn't realise, but it's back now)