RDoc Doesn't like quoted symbols

[Trans]

When running rdoc against Facets it reports a number of mesages like
this:

lib/facet/kernel/generate_method_name.rb:15:20: ':' not followed by
identified or operator

Line 15 is:

return :"_#{s}_"

This is perfectly legal Ruby, so I don't think RDoc should be throwing
warnings about it.

Thanks,
T.