Module lazy

Completely stolen from https://github.com/mgattozzi/whorl/blob/5e61714acf7d29e2b97cd26f6f0587060fa652cf/src/lib.rs#L306

Structs

Lazy

We want to have a static value that’s set at runtime and this executor will only use libstd. As of 10/26/21, the lazy types in std are still only on nightly and we can’t use another crate, so crates like once_cell and lazy_static are also out. Thus, we create our own Lazy type so that it will calculate the value only once and only when we need it.