Function infer_instantiations 

pub fn infer_instantiations(
    stmts: &[Stmt<'_>],
    interner: &Interner,
    registry: &TypeRegistry,
) -> Instantiations

Check stmts as far as each statement goes — a failing statement does not stop the rest — and answer what every generic site was solved at. The input to monomorphization; a backend with no generics of its own reads which instance each call and construction needs from here.