Add bdd_negation_union to avoid union blow-up (fixes macro.ex 4s slowdown)

Author: gldubc

lib/elixir/lib/module/types/descr.ex

@@ -5879,7 +5879,7 @@ defmodule Module.Types.Descr do
             end
 
           {:eq, _, {lit, c2, u2, _d2}} ->
-            {lit, bdd_negation(bdd_union(c2, u2)), :bdd_bot, :bdd_bot}
+            {lit, bdd_negation_union(c2, u2), :bdd_bot, :bdd_bot}
 
           {:eq, {lit, _c1, u1, d1}, _} ->
             {lit, :bdd_bot, :bdd_bot, bdd_union(d1, u1)}
@@ -5901,6 +5901,10 @@ defmodule Module.Types.Descr do
   defp bdd_difference_union(i, u1, u2),
     do: bdd_difference(i, bdd_union(u1, u2))
 
+  defp bdd_negation_union(u1, u2) do
+    bdd_intersection(bdd_negation(u1), bdd_negation(u2))
+  end
+
   ## Optimize differences
 
   defp bdd_difference(bdd_leaf(_, _) = a1, bdd_leaf(_, _) = a2, leaf_compare) do