Allow compilation of patterns to succeed even when the variables of the...

Allow compilation of patterns to succeed even when the variables of the expected input type cannot be erased.

types/patterns.ml

@@ -1403,9 +1403,15 @@ module Compile = struct
 
 
   let make_branches t b =
+    let open Debug in
+    _DEBUG "pat_comp" "@[make_branches type is: %a@]@\n" Types.Print.pp_type t;
     try
       make_branches t b
     with
-    FindCode -> make_branches (Types.Subst.hide_vars t) b
+      FindCode ->
+      try
+	make_branches (Types.Subst.hide_vars t) b
+      with
+	FindCode -> make_branches Types.any b
 
 end