Expose function names

[jdonszelmann]

It should be possible to query the name of the function, while you are iterating over it. This will mean that the functions will need to be stored in a hashmap.

[jdonszelmann]

for example:

create_annotatation!(fn test() -> (););

#[test::annotate]
fn my_fn() {
    println!("Test!");
}

fn main() {
    println!("calling all 'test' label");
    // using iter you can go through all functions with this annotation.
    for name, i in test::iter_named() {
       assert_eq!(name, "my_fn");
    }
}