Add TODOs

Author: sjakobi

Data/HashMap/Internal.hs

@@ -2386,6 +2386,10 @@ disjointArrays !s !bmA !aryA !bmB !aryB = go (bmA .&. bmB)
         iB = sparseIndex bmB m
 {-# INLINE disjointArrays #-}
 
+-- TODO: GHC 9.12.2 inlines disjointCollisions into `disjoint @Int`.
+-- How do you prevent this while preserving specialization?
+--
+-- TODO: GHC 9.12.2 also likes to rebox aryA when it is _not_ inlined. :/
 disjointCollisions :: Eq k => Hash -> A.Array (Leaf k a) -> Hash -> A.Array (Leaf k b) -> Bool
 disjointCollisions !hA !aryA !hB !aryB
   | hA == hB = A.all predicate aryA