[swift-evolution] Remove isUniquelyReferenced or isUniquelyReferencedNonObjC?

[Chris Eidhof]

There are two functions isUniquelyReferencedNonObjC and isUniquelyReferenced, which do exactly the same thing. One has a more constrained type, only accepting Swift objects. The other one accepts ObjC objects as well, but always returns false. Regardless of whether it should (could?) work for ObjC objects, I think this duplication is confusing (it has confused me for a long time, and I’m happy that I can now see they’re implemented in exactly the same way).

I think probably accepting just Swift objects would be the right thing to do, as the function is useless for ObjC objects.

Chris