size_t to dynamic

Depending on the OS, architecture, and compiler used `size_t` can sometimes be boxed into dynamic. Would be nice to add proper support for boxing `size_t` as it would make more sense for the `View` type to use it. Might be a bit tricker than the existing numeric types though as the size of `size_t` will vary between 4 and 8 bytes, so what should it report it's type as?