no_new_pseudos

[Richard Kenner]

> Am I the only one who completely fails to see the point of the
> spelling change?  I realize that you have said you find negative
> predicates confusing - I don't, but I do find changing predicates
> confusing.  I applaud cleaning up the definition and/or replacing it
> with a macro, and I'd applaud adding some extra internals
> documentation about it, but I think the fact that it's been called
> no_new_pseudos for so long suggests that we should just leave it
> called that if we want a predicate that means the same thing.

The reason to change it is that no_new_pseudos has been misused in the
past to both refer to what it's supposed to mean and to talk about
specific points in the compilation.  If we pick a new name (I don't think
anybody cares about the negative or positive distinction) we avoid
perpetuating that history.