Function run_state 

pub fn run_state<'b, F: for<'a> FnMut(&mut State<'a, 'b>)>(
    is_guest: bool,
    is_wasmtime_guest: bool,
    f: F,
) -> TokenStream

Create a State with all of its &mut references pointing to sensible things, run a function that emits code into the state, and then generate a token stream representing everything emitted