RFR(M): 8027422: assert(_gvn.type(obj)->higher_equal(tjp)) failed: cast_up is no longer needed

[Roland Westrelin]

> I was going to suggest it too but then you need additional methods for other methods: join(), higher_equal(), filter(). So I am fine with it if you do all of them.

Thanks, Vladimir. I’ll send an updated webrev.

Roland.