Use reinterpret cast is [does|may]PointTo

Instead of a straight up cast. Avoids problems related to opCast or alias this, such as those in:
http://forum.dlang.org/thread/vldwvnuivsfwjozqiuup@forum.dlang.org
I figured the fact that it links at all was a good indication it was working correctly. I need to change the alias this to also be a unlinked symbol. That should be good enough?