Function register_compatibility 

pub fn register_compatibility(from: TypeExpr, to: TypeExpr)

Register a type-compatibility edge from from to to.

Compatibility is directional; call twice for bidirectional compatibility.

use daedalus_data::model::{TypeExpr, ValueType};
use daedalus_data::typing::{register_compatibility, can_convert_typeexpr};

register_compatibility(
    TypeExpr::Scalar(ValueType::I32),
    TypeExpr::Scalar(ValueType::Int),
);
assert!(can_convert_typeexpr(
    &TypeExpr::Scalar(ValueType::I32),
    &TypeExpr::Scalar(ValueType::Int),
));