ru_local :: Bool, -- The fn at the head of the rule is
-- defined in the same module as the rule
- -- Orphan-hood; see comments is InstEnv.Instance( is_orph )
+ -- Orphan-hood; see Note [Orphans] in InstEnv
ru_orph :: Maybe OccName }
| BuiltinRule { -- Built-in rules are used for constant folding