Function structurally_relate_consts

pub fn structurally_relate_consts<I: Interner, R: TypeRelation<I>>(
    relation: &mut R,
    a: I::Const,
    b: I::Const,
) -> RelateResult<I, I::Const>

Relates a and b structurally, calling the relation for all nested values. Any semantic equality, e.g. of unevaluated consts, and inference variables have to be handled by the caller.

FIXME: This is not totally structural, which probably should be fixed. See the HACKs below.