[Bug libstdc++/60448] swap_ranges does not use ADL correctly

[public at alisdairm dot net]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=60448

--- Comment #1 from Alisdair Meredith <public at alisdairm dot net> ---
Created attachment 32287
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=32287&action=edit
Cleaner tagging scheme for the local class

Simplified the example to more directly expose the local class via ADL without
any funky casts.