How widely used are <ext/hash_set> and <ext/hash_map>?

[Joe Buck]

The thread arguing about this has gone on for a while, so I think
it's time to gather some data to answer the question of just how bad
it will be if we accept the decision to move ext/hash_set and ext_hash_map
into a different directory and to deprecate them.

Any of you out there who put out distros or port collections: how many 
packages in your distro use these classes?  You can grep for

'# *include *<ext/hash'

I'm particularly interested in the "Debian number", since the package
collection is so large.  Other information about use of these classes
will be interesting as well.