Function validate_resolvable 

fn validate_resolvable(
    db: &RootDatabase,
    scope: &SemanticsScope<'_>,
    mod_path: impl Fn(ItemInNs) -> Option<ModPath>,
    scope_filter: impl Fn(ItemInNs) -> bool,
    candidate: &NameToImport,
    resolved_qualifier: ItemInNs,
    unresolved_qualifier: &[Name],
    complete_in_flyimport: CompleteInFlyimport,
) -> SmallVec<[LocatedImport; 1]>

Validates and builds an import for resolved_qualifier if the unresolved_qualifier appended to it resolves and there is a validate candidate after that.